adding a clear message when overriding the android gradle plugin version
adding a clear message when overriding the android gradle plugin version

to prevent accidentally overriding it

Change-Id: I3c2f52931bd90a0d3ab3a1e979ebe8128b0fa2b2

AndroidX/androidx,androidx/androidx,AndroidX/androidx,androidx/androidx,androidx/androidx,AndroidX/androidx,androidx/androidx,AndroidX/androidx,androidx/androidx,AndroidX/androidx,AndroidX/androidx,androidx/androidx,androidx/androidx,AndroidX/androidx,AndroidX/androidx,androidx/androidx,androidx/androidx,androidx/androidx,AndroidX/androidx,AndroidX/androidx