Update the "host" bionic code tzdata lookup logic

The "if defined(__ANDROID__)" else branch is there to support
bionic when running on host environments.

The code now checks the
${ANDROID_RUNTIME_ROOT}/etc/tz/tzdata path as well.

This is similar to the current on-device expectations.

Eventually, we may remove the /system / ANDROID_ROOT cases.

Bug: 119293618
Test: build only
Change-Id: I8310f7b5a1c14567a648673970c636c7c84ff818