Ignore native bridge archs for apex selection

This leads to an arm64 apex being used on a device that is mixed
x86_64 with nativebridge=arm64. A device like that doesn't appear
to work with arm64 binaries. For example, the boringssl-self-check
binary crashes on boot.

Bug: 260115309
Test: unit test
Test: boot emulator with this combination
Change-Id: Ic4a91974290a05b1799f755fcf52ef226d68f4c2