Adapt chage note to new format

Author: atorralba

java/change-notes/2021-10-20-android-fragment-injection-query.md renamed to java/ql/src/change-notes/2021-12-15-android-fragment-injection-query.md

@@ -1,3 +1,5 @@
-lgtm,codescanning
+---
+category: newQuery
+---
 * Two new queries, "Android fragment injection" (`java/android/fragment-injection`) and "Android fragment injection in PreferenceActivity" (`java/android/fragment-injection-preference-activity`) have been added.
 These queries find exported Android activities that instantiate and host fragments created from user-provided data. Such activities are vulnerable to access control bypass and expose the Android application to unintended effects.