Manually Bump dev/benchmarks/platform_views_layout to AGP 9 #185221

Instead of including this change in this massive PR: #185118, bumping dev/benchmarks/platform_views_layout to AGP 9 will be done in a separate PR in case this change brings down the tree or affects a roll.

Added dev/benchmarks/platform_views_layout to the generate lockfiles exclusions.yaml because AGP 9 is incompatible with the current pinned google_mobile_ads version 5.1.0. The flutter platform_views_layout project can successfully build when google_mobile_ads is version 7.0.0, but webview_flutter has to be at least 4.10.0 and webview_flutter_android has to be at least 4.10.9.

Also, google_mobile_ads was manually pinned to 5.1.0 due to this xcode issue: #156912. It looks resolved, but included it just in case it isn't.

google_mobile_ads -> 7.0.0
webview_flutter -> 4.10.0
webview_flutter_android -> 4.10.9