ANR when viewing hierarchy

[seadowg]

Blocked by #5420

It's possible to get an ANR when switching the form hierarchy because question answers (which might be select choices) are loaded on the UI thread.

Here's an example report on Firebase: https://console.firebase.google.com/project/api-project-322300403941/crashlytics/app/android:org.odk.collect.android/issues/7008892868d636bf1de977208e794766?time=last-seven-days&types=ANR&sessionEventKey=6718E7D5026C000179EA52BFDE85A64E_2007392971344283898.

Example stacktrace:

          main (runnable):tid=1 systid=30278 
       at java.util.ArrayList.get(ArrayList.java:434)
       at org.javarosa.core.model.instance.TreeReference.getName(TreeReference.java:126)
       at org.javarosa.core.model.instance.DataInstance.resolveReference(DataInstance.java:84)
       at org.javarosa.xpath.expr.XPathPathExprEval.removeIrrelevantNodesets(XPathPathExprEval.java:42)
       at org.javarosa.xpath.expr.XPathPathExprEval.eval(XPathPathExprEval.java:35)
       at org.javarosa.xpath.expr.XPathPathExpr.eval(XPathPathExpr.java:213)
       at org.javarosa.xpath.expr.XPathPathExpr.eval(XPathPathExpr.java:60)
       at org.javarosa.xpath.expr.XPathFuncExpr.eval(XPathFuncExpr.java:187)
       at org.javarosa.xpath.expr.XPathEqExpr.eval(XPathEqExpr.java:56)
       at org.javarosa.xpath.expr.XPathBoolExpr.eval(XPathBoolExpr.java:43)
       at org.javarosa.core.model.condition.RawFilterStrategy.filter(RawFilterStrategy.java:32)
       at org.javarosa.core.model.condition.EvaluationContext.filterWithPredicate(EvaluationContext.java:382)
       at org.javarosa.core.model.condition.EvaluationContext.lambda$filterWithPredicate$0(EvaluationContext.java:383)
       at org.javarosa.core.model.ComparisonExpressionCacheFilterStrategy.filter(ComparisonExpressionCacheFilterStrategy.java:52)
       at org.javarosa.core.model.condition.EvaluationContext.filterWithPredicate(EvaluationContext.java:382)
       at org.javarosa.core.model.condition.EvaluationContext.lambda$filterWithPredicate$0(EvaluationContext.java:383)
       at org.javarosa.core.model.EqualityExpressionIndexFilterStrategy.filter(EqualityExpressionIndexFilterStrategy.java:33)
       at org.javarosa.core.model.condition.EvaluationContext.filterWithPredicate(EvaluationContext.java:382)
       at org.javarosa.core.model.condition.EvaluationContext.filterWithPredicate(EvaluationContext.java:377)
       at org.javarosa.core.model.condition.EvaluationContext.expandReferenceAccumulator(EvaluationContext.java:343)
       at org.javarosa.core.model.condition.EvaluationContext.expandReference(EvaluationContext.java:250)
       at org.javarosa.core.model.condition.EvaluationContext.expandReference(EvaluationContext.java:219)
       at org.javarosa.xpath.expr.XPathPathExprEval.eval(XPathPathExprEval.java:34)
       at org.javarosa.xpath.expr.XPathPathExpr.eval(XPathPathExpr.java:213)
       at org.javarosa.xpath.XPathConditional.evalNodeset(XPathConditional.java:94)
       at org.javarosa.core.model.ItemsetBinding.getChoices(ItemsetBinding.java:125)
       at org.javarosa.form.api.FormEntryPrompt.getSelectChoices(FormEntryPrompt.java:222)
       at org.javarosa.form.api.FormEntryPrompt.getAnswerValue(FormEntryPrompt.java:98)
       at org.javarosa.form.api.FormEntryPrompt.getAnswerText(FormEntryPrompt.java:154)
       at org.odk.collect.android.formhierarchy.QuestionAnswerProcessor.getQuestionAnswer(QuestionAnswerProcessor.kt:28)
       at org.odk.collect.android.formhierarchy.FormHierarchyActivity.refreshView(FormHierarchyActivity.java:672)
       at org.odk.collect.android.formhierarchy.FormHierarchyActivity.refreshView(FormHierarchyActivity.java:591)
       at org.odk.collect.android.formhierarchy.FormHierarchyActivity.onCreate(FormHierarchyActivity.java:278)
       at org.odk.collect.android.formhierarchy.ViewOnlyFormHierarchyActivity.onCreate(ViewOnlyFormHierarchyActivity.kt:16)
       at android.app.Activity.performCreate(Activity.java:8936)
       at android.app.Activity.performCreate(Activity.java:8900)
       at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1456)
       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:4287)
       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:4459)
       at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:103)
       at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:139)
       at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:96)
       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2853)
       at android.os.Handler.dispatchMessage(Handler.java:108)
       at android.os.Looper.loopOnce(Looper.java:226)
       at android.os.Looper.loop(Looper.java:328)
       at android.app.ActivityThread.main(ActivityThread.java:9223)
       at java.lang.reflect.Method.invoke(Native method)
       at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:594)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)

Notes

Once this is fixed, we should be able to remove the StrictMode workarounds for the hierarchy added in #6456.