Clarify some comments on individual key codes.
Clarify some comments on individual key codes.

Change-Id: I03cce0ad69aaab5b71e5017982b01afd27285d2f

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