Move StrictMode timers to postAtFrontOfQueue().

StrictMode posts a message to estimate how long the main thread was
blocked during a violation.  Currently, any pending messages are
counted against the violation.  To avoid this, switch to using
postAtFrontOfQueue().

Bug: 6119289
Change-Id: I94530632ca678b78b75a698cf9193641b102be9a
1 file changed