Added test for uninstalling a package with active admins

Added a ui automater test to uninstall a package with active admins from
settings. The test installs an empty device admin package, activates the
device admin component and performs the ui interactions to uninstall the
package through settings. At the end of the test it verifies whether the
package was successfully uninstalled.

Bug: b/22359208
Change-Id: I5e36bd8129a0cf20f2c22c76f9ed4e5e3eba9b15
10 files changed