[android] - post camera updates to the end of the message queue

[tobrun]

Targets release branch, extracted from #6532.

This PR allows to call new animations directly from the onFinish from another. Prior this fix one camera update cancelled the other because it was still resolving his onFinish event. Side effect, this mostly solves #6769 (definitive solution in #6999).

Review @ivovandongen

[mention-bot]

@tobrun, thanks for your PR! By analyzing the history of the files in this pull request, we identified @clydebarrow, @cammace and @ivovandongen to be potential reviewers.

[tobrun]

In 1938de2 I removed the camera related unit tests. These don't work with runnables, fwiw in #6803 targetting master I removed the unit tests as well in favour of a instrumentation tests.

[ivovandongen]

@tobrun Running UI tests on this locally, I get a failure on com.mapbox.mapboxsdk.testapp.activity.gen.annotation.MarkerViewActivityTest#testSanity:

11-11 16:14:16.195 24081-24081/com.mapbox.mapboxsdk.testapp A/art: art/runtime/java_vm_ext.cc:470] JNI DETECTED ERROR IN APPLICATION: JNI CallVoidMethodV called with pending exception java.lang.NullPointerException: Attempt to read from field 'double com.mapbox.mapboxsdk.camera.CameraPosition.tilt' on a null object reference
11-11 16:14:16.195 24081-24081/com.mapbox.mapboxsdk.testapp A/art: art/runtime/java_vm_ext.cc:470] (Throwable with no stack trace)
11-11 16:14:16.195 24081-24081/com.mapbox.mapboxsdk.testapp A/art: art/runtime/java_vm_ext.cc:470]     in call to CallVoidMethodV
11-11 16:14:16.195 24081-24081/com.mapbox.mapboxsdk.testapp A/art: art/runtime/java_vm_ext.cc:470]     from void android.os.MessageQueue.nativePollOnce(long, int)
11-11 16:14:16.195 24081-24081/com.mapbox.mapboxsdk.testapp A/art: art/runtime/java_vm_ext.cc:470] "main" prio=5 tid=1 Runnable
11-11 16:14:16.195 24081-24081/com.mapbox.mapboxsdk.testapp A/art: art/runtime/java_vm_ext.cc:470]   | group="main" sCount=0 dsCount=0 obj=0x755ad000 self=0xe7085400
11-11 16:14:16.195 24081-24081/com.mapbox.mapboxsdk.testapp A/art: art/runtime/java_vm_ext.cc:470]   | sysTid=24081 nice=0 cgrp=default sched=0/0 handle=0xe9c98534
11-11 16:14:16.195 24081-24081/com.mapbox.mapboxsdk.testapp A/art: art/runtime/java_vm_ext.cc:470]   | state=R schedstat=( 4828028062 787604601 5778 ) utm=303 stm=178 core=0 HZ=100
11-11 16:14:16.195 24081-24081/com.mapbox.mapboxsdk.testapp A/art: art/runtime/java_vm_ext.cc:470]   | stack=0xff566000-0xff568000 stackSize=8MB
...

[tobrun]

That was a valid bug, fixed it up in d941cde.