Soong: Add synopsis to cc_library_* modules

Added synopsis to the following modules under cc package:
   * cc_library_static
   * cc_library_shared
   * cc_library
   * cc_library_host_static
   * cc_library_host_shared
   * cc_library_headers

Bug: b/128337482
Test: Generated the documentation and verified that the synopsis was
added to each of the module.

Change-Id: I4d9bb622dc75aad9ea1b9f331c80ed56ddbc9a15