LOAndroid2: use GLES2, latest GeckoSoftwareLayerClient

Additionally add GeckoGLLayerClient as an alternative LayerClient

Change-Id: I250b5d806f520231ad9a9b84ef8387e8830bb364
LODroid2: Remove sdk v7 and v4 support libraries

Change-Id: I41a30d44c44cb439dc2e60e212eea18b00f316dd
LODroid2: GLES2 fixes, code cleanup

Change-Id: I368f8caaf0433387a330a63182aab292defef0ca