Add current build release

Previously, the build releases only included named releases so did not
have a way to represent the latest build release. This adds the current
build release (named after the current API level) to represent that.

Bug: 240406019
Test: m nothing
Change-Id: Ib8336da716b447448b23bc9684ce3be1ab78648a
(cherry picked from commit 42a49f12)
Merged-In: Ib8336da716b447448b23bc9684ce3be1ab78648a