Create an AppEntitiesHeader widget

- Create a library named EntityHeaderWidgets, it can contains
  other entity header wdigets in the future.
- Create a controller of AppEntitiesHeader,
  then user can initialize its view easily.

Test: visual, robotest
Change-Id: If11b3eba75334f66b72472b2139e0e7d93984dce
Fixes: 117621156
diff --git a/packages/SettingsLib/Android.bp b/packages/SettingsLib/Android.bp
index cc17b25..0126e7e5 100644
--- a/packages/SettingsLib/Android.bp
+++ b/packages/SettingsLib/Android.bp
@@ -18,6 +18,7 @@
         "SettingsLibSettingsSpinner",
         "SettingsLayoutPreference",
         "ActionButtonsPreference",
+        "SettingsLibEntityHeaderWidgets",
     ],
 
     // ANDROIDMK TRANSLATION ERROR: unsupported assignment to LOCAL_SHARED_JAVA_LIBRARIES