Convert *-developer-gsi.avbpubkey to Android.bp

Use `soong_config_module_type` to install `*-developer-gsi.avbpubkey`
to either `ramdisk` or `vendor_ramdisk` based on the value of
`BOARD_MOVE_GSI_AVB_KEYS_TO_VENDOR_BOOT` in each device.

In build/soong/android/paths.go's modulePartition() function, there is
already logic to construct `vendor_ramdisk` and `ramdisk` partitions
based on the different values of
`BOARD_MOVE_RECOVERY_RESOURCES_TO_VENDOR_BOOT` and
`BOARD_USES_RECOVERY_AS_BOOT`. And the logic is identical to the
original Android.mk.

Therefore, this change only needs to determine whether the avb public
keys should be placed in `vendor_ramdisk` or `ramdisk` based on the
value of `BOARD_MOVE_GSI_AVB_KEYS_TO_VENDOR_BOOT`. The rest of the
judgment logic can be ignored.

Bug: 347636127
Test: 1) lunch aosp_cf_x86_64_phone && m q-developer-gsi.avbpubkey
      2) check it installed to vendor_ramdisk/first_stage_ramdisk/avb/
      3) lunch yukawa && m q-developer-gsi.avbpubkey
      4) check it installed to ramdisk/avb/q-developer-gsi.avbpubkey
Change-Id: I6de1a038261f2feeae4504d8097c7392b166848d