Add //apex_available:platform to libicing_tests am: 5d29d40264

Original change: https://android-review.googlesource.com/c/platform/external/icing/+/3483480

Change-Id: Iabc69e6f648e9e3bf07284eaad62c219767097f6
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

Android.bp

diff --git a/Android.bp b/Android.bp
index 747e493..0b038f5 100644
--- a/Android.bp
+++ b/Android.bp
@@ -150,6 +150,7 @@
         "libprotobuf-cpp-lite",
         "libz",
     ],
+    apex_available: ["//apex_available:platform"],
 }
 
 // TODO(cassiewang): Add build rules and a TEST_MAPPING for cc_tests