Ensure the resource name is validated

According to the comment of FabricatedOverlaysTests#setResourcesValue,
it describes that the param `resourceName` should be in the form
"[package]:type/entry". However, there is no validation for it.

This patch adds the function ensureValidResourceName to validate the
input param resourceName.

Bug: 205919743

Test: atest OverlayDeviceTests
      # result is http://ab/I87000010106296791

Change-Id: I3327feafe297b697ae295e7a417cba581c482726