Revert "Using Android R pdfium variant for pdfclient_test, since..."

Revert submission 32238120-pdfium-android-r-compatible

Reason for revert: Droidmonitor created revert due to b/405377467. Will be verifying through ABTD before submission.

Reverted changes: /q/submissionid:32238120-pdfium-android-r-compatible

Change-Id: I9df0566f61b20a23c31fa760c4477cc37d49cf11
1 file changed