Merge "frameworks/base: acquire lock on am only when needed"

diff --cc services/java/com/android/server/am/ActivityManagerService.java
index 883fdda,92721fe..d24ce7e
mode 100755,100644..100644
--- 1/services/java/com/android/server/am/ActivityManagerService.java
--- 2/services/java/com/android/server/am/ActivityManagerService.java
+++ b/services/java/com/android/server/am/ActivityManagerService.java