Change bug component for LevelDBProto component

Up until now, LevelDB Proto DB has shared the bug component with the
rest of Internals. This CL changes it to use the newly created
Internals>Storage>LevelDBProto bug component.

Bug: 1023496
Change-Id: Ief55a3616d90e6a6790ad21fc7935a5a2753eb38
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1907078
Auto-Submit: Tommy Nyquist <nyquist@chromium.org>
Commit-Queue: ssid <ssid@chromium.org>
Reviewed-by: ssid <ssid@chromium.org>
Cr-Commit-Position: refs/heads/master@{#714779}

components/leveldb_proto/OWNERS

 nyquist@chromium.org
 ssid@chromium.org
 
-# COMPONENT: Internals
+# COMPONENT: Internals>Storage>LevelDBProto
 # TEAM: chromium-reviews@chromium.org