update robots.txt to disallow the community/ pages
update robots.txt to disallow the community/ pages

Change-Id: I318308f7219b296d92039cba2b6f5ace321f697f

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