delete 'templates-sdk-dev', all these files were merged back into...

delete 'templates-sdk-dev', all these files were merged back into 'templates-sdk' with this CL: https://googleplex-android-review.git.corp.google.com/#/c/1394582/ and this depends on the following CL to update all the doc build targets: https://googleplex-android-review.git.corp.google.com/#/c/1406302/ am: 6c8efecb am: 21c9005f am: 22f2435e
am: 5cdd592c

Change-Id: I76167406f900f2a70fe4592a463944829e199921