DevicePolicyManager Tests

Bug 4562272

Create a package to house the DeviceAdminReceiver. This package
must be installed and activated prior to the test much like
how the Accessibility tests work.

Add tests that instrument the receiver's package so that they
can call the DevicePolicyManager methods without getting
security exceptions.

Change-Id: Iefec1ccec97709e8154fecb3c149e3f4e9ab7328