Preserve GLSurfaceView's EGL context on pause

[LukasPaczos]

Closes #12724.

The issue surfaced with the introduction of the GLSurfaceView - whenever activity containing a surface is paused, the surface releases the EGL context and forces the surface to be recreated upon coming back to the activity, which forces us to redraw the tiles.

This PR sets the PreserveEGLContextOnPause flag which tries to hold on to the EGL context when activity is paused, but only if the hardware allows for it. From documentation:

Whether the EGL context is actually preserved or not depends upon whether the Android device that the program is running on can support an arbitrary number of EGL contexts or not. Devices that can only support a limited number of EGL contexts must release the EGL context in order to allow multiple applications to share the GPU.

Before:

After:

[tobrun]

Tested on 5 different devices with different OS versions.
LGTM,

[saugs]

Sorry to comment on an old subject, but is that merge effective on android SDK 7.5.0-beta.1 ?

Because I'm still experiencing issue : mapview's GLSurfaceView is being recreated after onResume.
For now I'm using TextureView (mapbox:mapbox_renderTextureMode).

[LukasPaczos]

@SeboRax, since this has landed, we've made changes to the GLSurfaceView implementation to improve lifecycle and introduce recycler view support. Unfortunately, those changes required recreation of the context/surface which forces tiles to reload that is seen in the OP. This is working as intended now.

[saugs]

Ok thanks for your answer, I'll stay using TextureView for now