Don't acquire WM service lock in ActivityStackSupervisor.resolveIntent()

The lock isn't really needed in this method since it doesn't touch any
internal state to the service. This helps us avoid a deadlock where
package manager calls back in AMS.

Change-Id: I73ba11c11f91fbd671d5a8775d31afb48eebca9d
Fixes: 120113767
Test: N/A