Remove NearbyUnitTests[com.google.android.nearby.apex] from mainline
test mapping.

Bug: 193602229

Test: unittests
Change-Id: I9271a9303640e024af03862bf9708243bc1ea734
diff --git a/nearby/TEST_MAPPING b/nearby/TEST_MAPPING
index 8bc5bc6..f8e2afd 100644
--- a/nearby/TEST_MAPPING
+++ b/nearby/TEST_MAPPING
@@ -8,10 +8,11 @@
     {
       "name": "NearbyUnitTests"
     }
-  ],
-  "mainline-presubmit": [
-    {
-      "name": "NearbyUnitTests[com.google.android.nearby.apex]"
-    }
   ]
-}
\ No newline at end of file
+  // TODO(b/193602229): uncomment once it's supported.
+  //"mainline-presubmit": [
+  //  {
+  //    "name": "NearbyUnitTests[com.google.android.nearby.apex]"
+  //  }
+  //]
+}