Ensure database is closed even if ending transaction fails

If endTransaction() throws an exception then previously
close() would not be called.  This adds another try/catch
block that only ends the transaction if begin transaction
successfully completes and closes the database consistently
across multiple method calls that may raise exceptions

Author: kevinsawicki

app/src/main/java/com/github/mobile/persistence/DatabaseCache.java

@@ -85,12 +85,13 @@ private <E> List<E> requestAndStore(SQLiteOpenHelper helper,
         SQLiteDatabase db = helper.getWritableDatabase();
         try {
             db.beginTransaction();
-
-            persistableResource.store(db, items);
-
-            db.setTransactionSuccessful();
+            try {
+                persistableResource.store(db, items);
+                db.setTransactionSuccessful();
+            } finally {
+                db.endTransaction();
+            }
         } finally {
-            db.endTransaction();
             db.close();
         }
         return items;