Add used Apis in documentsUI to mts

Test: atest of every individual test in the test plan for Q devices
Bug: 195210087, 160006699

Change-Id: If82db42e7cdfa8d44565429e4ed9ae2591316cf5
(cherry picked from commit f2b406635c4473710947e3c1c69fc1e51d4f812b)
diff --git a/tests/tests/content/Android.bp b/tests/tests/content/Android.bp
index b808b6b..9ada51d 100644
--- a/tests/tests/content/Android.bp
+++ b/tests/tests/content/Android.bp
@@ -107,6 +107,7 @@
     test_suites: [
         "cts",
         "general-tests",
+        "mts",
     ],
     min_sdk_version: "29",
 }
diff --git a/tests/tests/provider/Android.bp b/tests/tests/provider/Android.bp
index f383b24..c979102 100644
--- a/tests/tests/provider/Android.bp
+++ b/tests/tests/provider/Android.bp
@@ -13,6 +13,7 @@
         "cts",
         "general-tests",
         "sts",
+        "mts",
     ],
 
     libs: [