[InstalledApp] Add OWNERS file.

Add OWNERS file for installedapp directories in chrome/android/java.
These are the same owners of installedapp in other directories as well.

Change-Id: I75e24357d9c878e9009b8d4f370d5db5dade593e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1954477Reviewed-by: Avi Drissman <avi@chromium.org>
Reviewed-by: Peter Beverloo <peter@chromium.org>
Commit-Queue: Avi Drissman <avi@chromium.org>
Auto-Submit: Rayan Kanso <rayankans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#722529}

chrome/android/java/src/org/chromium/chrome/browser/installedapp/OWNERS

+peter@chromium.org
+rayankans@chromium.org
+
+# COMPONENT: Platform>Apps>AppLauncher>Install

chrome/android/junit/src/org/chromium/chrome/browser/installedapp/OWNERS

+peter@chromium.org
+rayankans@chromium.org
+
+# COMPONENT: Platform>Apps>AppLauncher>Install