Revert "WebView: add custom TargetPreparer"

This reverts commit d74da827ed716890f130ac71b511d2b085c25909.

Reason for revert: Droidmonitor created revert due to b/428964345. Will be verifying through ABTD before submission.

Fix: 428964345
Change-Id: Icfffe66088401dc1e3690df134ea7a037a9eb8a9
8 files changed