Update uiautomator references in libraries/flicker

* Remove unused dependencies.
* Replace "ub-uiautomator" (v2.2.0) with
  "androidx.test.uiautomator_uiautomator" (v2.3.0).

Bug: 235842600
Test: presubmit
Change-Id: I3441eaec744b26bf837f79b66c7e2ebf4e8559c3
1 file changed