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: 3b7b490e
am: c826b830

Change-Id: I523052bf332196ebb79d0b4bfa3ba2c7bc2c7de9