Add doc for View.getElevation()
Add doc for View.getElevation()

Change-Id: I5a843969fa03db6bb0faef80962c1256c64aa450

xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base