Android: Suppress unused resource warning for *_expand_*

Suppression was recently removed, but it looks to still by needed for
chromecast targets:
https://ci.chromium.org/p/chromium/builders/try/cast_shell_android/592386

Bug: 1017190
Change-Id: I42db833add3ce07718e3f7d5ebfa66ff153ccc43
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2306581
Commit-Queue: Andrew Grieve <agrieve@chromium.org>
Commit-Queue: Peter Wen <wnwen@chromium.org>
Auto-Submit: Andrew Grieve <agrieve@chromium.org>
Reviewed-by: Peter Wen <wnwen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#789979}

build/android/lint/suppressions.xml

@@ -376,6 +376,8 @@ Still reading?
     <ignore regexp="android_webview/test/shell/res/raw/resource_file.html"/>
     <ignore regexp="android_webview/test/shell/res/raw/resource_icon.png"/>
     <ignore regexp="android_webview/tools/automated_ui_tests/java/res/layout/"/>
+    <!-- 1: resource in //ui because it's used by multiple deps. -->
+    <ignore regexp="The resource `R.drawable.*_expand_.*` appears to be unused"/>
     <!-- 3: WebView uses some //components/browser_ui resources, but not all (crbug.com/1099842). -->
     <ignore regexp="components/browser_ui/styles/"/>
     <ignore regexp="components/browser_ui/widget/"/>