Translate SDK level 10000 to a valid compiler min-api

Targets with the special level 10000 are compiled using the current
platform SDK level. They are also compiled as a "platform build" which
will disable features such as API modeling and method backports.

Bug: 295591477
Test: manual inspection of the updated build commands
Change-Id: Ifda8859396b33dde4c46a9b212ddb855b012bf07