docs: add accepted values for setting status bar visibility
docs: add accepted values for setting status bar visibility

Change-Id: I67ef29f8ccc7b4a754ebb24efd96e9821e3d8662

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