Disable inernal app before running tests

Debuggable reamdump data collection dialog is triggering up while
running tests. These are causing flakes. While a better fix would be
figuring out why these are triaggered, the wm tests should be
independent of internal apps which an end user of Android won't see.

Test: Forrest
Bug: 258578781
Bug: 239384214
Change-Id: Ia4c0c670fe3e35f84640787cb8fce70e74edb264