AI 147084: am: CL 147083 am: CL 147081 Add document describing AVDs and usage. (doc change only)   Original author: ddougherty   Merged from: //branches/cupcake/...   Original author: android-build
AI 147084: am: CL 147083 am: CL 147081 Add document describing AVDs and usage. (doc change only)
  Original author: ddougherty
  Merged from: //branches/cupcake/...
  Original author: android-build

Automated import of CL 147084

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