Android.bp添加prebuilt lib

cc_prebuilt_library_shared {
    name: "lib",
    vendor: true,
    srcs: ["lib.so"],
}

cc_prebuilt_library_shared {
    name: "lib",
    vendor: true,
    target: {
        android_arm64: {
            srcs: ["lib.so"],
        },
    },
}