[automerger skipped] Merge changes from topics "add-certs-cp", "feature_BusyTone_for_DisconnectCause" am: 15ddba32e0 am: 510f917b94
am: 27b61580fe -s ours
am skip reason: SHA1 27b61580fe skipped by user hallliu

Change-Id: I2646ee95ddc238bb3f008f7e02ff0e6f18230dc9