Share apply token between WMCore and WMShell

This means WMShell/Core/Launcher are using the same
apply token.

Barring alternatives, this is necessary to make sure
that transitions work properly (since surface operations
span multiple process). Otherwise, even if transactions
are received by SF in the correct order, they can be
applied in a different order.

Bug: 256046837
Test: atest PipRotationTest_ShellTransit and check for leaked
      tasks in surface dump.
Change-Id: I0424e66ed347576718f62b1e598ae116720aa70d