Do I need to include another copyright notice in addition to the Google one at the bottom of the license? If so, how should I do that?
For anything licensed with the Apache 2 license, you must keep all relevant original copyright and attribution notices. You must also keep the NOTICES file, if there is one:
If the Work includes a "NOTICE" text file as part of its distribution, then any Derivative Works that You distribute must include a readable copy of the attribution notices contained within such NOTICE file, excluding those notices that do not pertain to any part of the Derivative Works, in at least one of the following places: within a NOTICE text file distributed as part of the Derivative Works; within the Source form or documentation, if provided along with the Derivative Works; or, within a display generated by the Derivative Works, if and wherever such third-party notices normally appear.
If there is no NOTICE file, you don't need to worry about that part.
Can I license the project as a whole under a different license if I'm using the starter kit or do I need to license it under the same license?
According to the text of the Apache 2 license, you can license your modifications, or your whole project, any way you like, but you can't change the license for the original code:
You may add Your own copyright statement to Your modifications and may provide additional or different license terms and conditions for use, reproduction, or distribution of Your modifications, or for any such Derivative Works as a whole, provided Your use, reproduction, and distribution of the Work otherwise complies with the conditions stated in this License.
See the text of the Apache 2 license for more information, especially section 4 ("Redistribution"). Note that I am not a lawyer and this is not legal advice.