Increase the broadcast timeout duration in the tests.

In the legacy queue, it is posssible that the broadcast
timeout is elapsed before the onApplicationAttachedLocked()
callback is received, which will result in the broadcast
receiver getting discarded.

Bug: 289108400
Test: atest services/tests/mockingservicestests/src/com/android/server/am/BroadcastQueueTest.java
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:dcd5c460abe8aaa1e89d5204f3d34343becc8e30)
Merged-In: Ic3456f0711d09a5d1e5549a326ad056bde939546
Change-Id: Ic3456f0711d09a5d1e5549a326ad056bde939546