Add apexd.mainline_patch_level_2 to PRODUCT_PACKAGES

identifies that the apexd has a fix included for go/mainline-play-installs-incident

Bug: 433787201
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:a89e1ec183c96413380b5e2db37581b7031d04ea)
Merged-In: I7bbd5c9db0144b2ceba0902819e19ce7e56e2985
Change-Id: I7bbd5c9db0144b2ceba0902819e19ce7e56e2985