libbpf_android: remove native_bridge_supported from Android.bp

This is a holdover from when libmeminfo depended on libbpf_android, a
dependency which has since been removed. Deleting it allows
libbpf_android to use libvintf, which will be used to identify a
device's kernel branch for BPF attach point enforcement.

Test: build
Change-Id: I73747e04c2a843652859e4fb753bd5afdedba1cd
Signed-off-by: Connor O'Brien <connoro@google.com>