Allow choosing rendering backend on Android during initialization

[louwers]

Please upvote this issue if you are interested in this, or leave a comment if you have additional context and implementation ideas.

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Is your feature request related to a problem? Please describe.

Allow a choosing between Vulkan and OpenGL ES rendering backend on Android on map initialization.

Describe the solution you'd like

On map initialization we should allow passing an enum value VULKAN, OPENGL or AUTO.

With the AUTO option we would detect what rendering backend is supported and default to that.

Describe alternatives you've considered

Releasing MapLibre Android with different backends as different libraries. This will happen starting 11.7.0:

• org.maplibre.gl:android-sdk (OpenGL)
• org.maplibre.gl:android-sdk-vulkan (Vulkan)

The downside of this is that there is some build and distribution complexity involved when building different apks and distributing those. It is also easier for other platforms that depend on MapLibre Android, like current implementations of MapLibre for Flutter, React Native and Kotlin Multiplatform, to intergrate.

The downside of using multiple libraries in one library is that the size of the library will increase. We should give people the option to use only Vulkan or only OpenGL ES, or configure their release process to distribute multiple apks. That is why I think that starting with MapLibre Android 12.0.0 we should publish the library as three different packages.

• org.maplibre.gl:android-sdk (OpenGL ES + Vulkan, defaulting to automatic selection)
• org.maplibre.gl:android-sdk-opengl (OpenGL ES)
• org.maplibre.gl:android-sdk-vulkan (Vulkan)

Additional context

A run-time switch (i.e. when the map is already initialized) is out of scope for this issue.

[Vichy97]

This would be great to be able to slowly roll out Vulkan based on a feature flag. Right now Vulkan seems very unstable so if I make the switch eventually I'd like to roll out slowly and monitor for crashes.