Add jshikaram as OWNERs of app management.

BUG=None

Change-Id: I02fe66229490c1ce1b264974d57eb84a0e4b5fe1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1737073
Commit-Queue: Dominick Ng <dominickn@chromium.org>
Commit-Queue: calamity <calamity@chromium.org>
Reviewed-by: Jeevan Shikaram <jshikaram@chromium.org>
Cr-Commit-Position: refs/heads/master@{#684230}

chrome/browser/resources/app_management/OWNERS

-calamity@chromium.org
 dominickn@chromium.org
-ericwilligers@chromium.org
+jshikaram@chromium.org
 
-# COMPONENT: Platform>Apps>Foundation
+# COMPONENT: Platform>Apps>Foundation
\ No newline at end of file

chrome/browser/ui/webui/app_management/OWNERS

 per-file *.mojom=set noparent
 per-file *.mojom=file://ipc/SECURITY_OWNERS
 
-calamity@chromium.org
 dominickn@chromium.org
-ericwilligers@chromium.org
+jshikaram@chromium.org