Remove INJECT_EVENTS permissions from test APKs.

This permission only applies to system apps, so the test APKs couldn't
actually use the permission.

BUG=502028

Review URL: https://codereview.chromium.org/1206323004

Cr-Original-Commit-Position: refs/heads/master@{#336938}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 90d3bdc22f7826554dc0221f08bcc035bc7d9e54

android/lint/suppressions.xml

@@ -83,8 +83,6 @@ Still reading?
     <ignore path="AndroidManifest.xml"/>
   </issue>
   <issue id="Overdraw" severity="ignore"/>
-  <!-- TODO(newt): remove if INJECT_EVENTS is not needed crbug.com/502028 -->
-  <issue id="ProtectedPermissions" severity="ignore"/>
   <issue id="Recycle" severity="ignore"/>
   <issue id="Registered" severity="ignore"/>
   <issue id="RtlCompat" severity="ignore"/>