Allow FMQ to be double-loaded

libfmq is a shared library. When it is included by an NDK library, it
produces the following error message:

module "libneuralnetworks" variant "android_arm64_armv8-2a_kryo385_core_static":
links VNDK library "libfmq" that isn't double loadable (not also LL-NDK,
VNDK-SP, or explicitly marked as 'double_loadable').

This CL allows FMQ to be double-loaded, enabling it to be used by NDK
libraries.

Test: mma
Change-Id: I421eb7a9e4b969f1f3ef415bd580a42ac8e747bb
(cherry picked from commit 2fbcc29d05fee97eba571f6fc8317b7c2b43d78f)
diff --git a/Android.bp b/Android.bp
index 89d675a..a2efbb5 100644
--- a/Android.bp
+++ b/Android.bp
@@ -12,10 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-subdirs = [
-    "tests",
-]
-
 cc_library {
     name: "libfmq",
     shared_libs: [
@@ -42,4 +38,5 @@
     vndk: {
         enabled: true,
     },
+    double_loadable: true,
 }