packages/apps/DocumentsUI: Add APCT tests to the device-tests suite.

This CL adds the APCT tests within this project to
a similar suite as CTS known as device-tests.

The current method of running APCT tests in the infrastructure
is unaffected.

Bug: 35882476
Test: `make dist device-tests -j` and local builds of
      continuous_instrumentation_tests & continuous_native_tests

Change-Id: Icdfc9684999b7289ca4a8b9f97caed04f5fcf245