Make CompanionDeviceManager.apk to platform signed

Inorder to make CompanionDeviceMananger to be able to
get appInfo from non-0 profile we need to add
android.permission.INTERACT_ACROSS_USERS permission and
make CompanionDeviceManager.ap platform signed.

Fix: 215160795
Test: atest CtsCompanionDeviceManagerCoreTestCases
      atest CtsCompanionDeviceManagerUiAutomationTestCases
      atest CtsOsTestCases:CompanionDeviceManagerTest

Change-Id: I26cebadcdef05274436cd454b4d635d82eb2b7e2
(cherry picked from commit bd4f2c2f)