VTS: Create a new ConnectedDisplaysTest

Create a new file that is part of the VtsHalGraphicsComposer3_ test
suite.
This file is meant to contain all tests that are directly related to the
presence of Connected Displays, to test the interaction dependent on
their presence.
another display is present.

Bug: b/391837864, b/355482219
Test: atest VtsHalGraphicsComposer3_TargetTest on AL with connected
display
Flag: TEST_ONLY

Change-Id: I92f7424c5d78fcf7c1c41b6dce0790497c8fb261