Fix PhonePolicyTest timeout

* PhonePolicyTest used to run too long (26 seconds plus) because it
  needs to wait for the reconnect timeout
* This CL fixes the test by
  1) Moving common setup code into setUp() method
  2) Using TestLooperManager to manually execute delayed handler
     messages immediately after they are posted

Bug: 68818803
Test: runtest -i -j40 bluetooth; adb shell am instrument -w -e
timeout_msec 300000 -e class
'com.android.bluetooth.btservice.PhonePolicyTest'
'com.android.bluetooth.tests/android.support.test.runner.AndroidJUnitRunner'
Change-Id: I4789e3427e1a5729be6f620d39da539f76767e57