chore: more license header updates (#1909)

* chore: update license headers again

- CSS, Gradle, Java, JS, TS: Formatted doc block style to use "/*" instead of "/**"
- HTML: Move license header below DOCTYPE
- Add missing license header
- Cleanup rat ignore

* chore: format cordova-js-src license headers

test/androidx/app/.gitignore

@@ -1 +1,18 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
 /build