Render exception when there is another Surface that also calls eglMakeCurrent

[zugaldia]

If an activity includes another Surface that also calls eglMakeCurrent() the app shows a number of EGL_BAD_DISPLAY crashes with the following exception on the Java side:

Caused by: java.lang.Error: eglSwapBuffers() failed
at com.mapbox.mapboxsdk.maps.NativeMapView.nativeRender(Native Method)
at com.mapbox.mapboxsdk.maps.NativeMapView.render(SourceFile:177)

This seems to be due to not resetting the firstRender flag in native_map_view.cpp. Resetting it to true on destroySurface() fixes it.

Additionally, we don't have any test activities with another (GL) surface to test this situation. We should add a new one to the Test App.

Possibly related: #6647.

cc: @ivovandongen @tobrun