git ignore .gradle/ and .settings/

These directories were created automatically, and should be ignored

Change-Id: I34bfc68c9f002523f52295b2d358cf3cbe66574a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1830109Reviewed-by: Richard Coles <torne@chromium.org>
Reviewed-by: Nate Fischer <ntfschr@chromium.org>
Commit-Queue: Dan H <harringtond@chromium.org>
Cr-Commit-Position: refs/heads/master@{#701323}

android_webview/support_library/boundary_interfaces/.gitignore

 # For Android Studio, when we mirror this repo into the Android tree
 *.iml
+.gradle/
+.settings/