Handle zygote_32_64 in gsi_release.mk

64 bits GSI expects supporting both zygote_64_32 and zygote_32_64.

The patch adds including init.zygote32_64.rc in gsi_release.mk
direclty, and also revises all GSI releasing build targets.

Bug: 138625977
Test: build aosp_arm64-userdebug and has init.zygote32_64.rc
Test: build aosp_arm-userdebug and no init.zygote32_64.rc
Change-Id: Ia61db1315321798bae8902b35ddaa5e5f3e7dd3e