Make DocumentsUIGoogleTests postsubmit tests running on real device.

Add "primary-device" property to TEST_MAPPING for testing real device.
Note: Currently, "primary-device" property only effected on Crosshatch
device.

Bug: 139258941
Test: atest DocumentsUIGoogleTests (on Crosshatch device)
Change-Id: I2bb3146a1400173a7037abfc0872ec42dd813b3b

1 files changed, 2 insertions, 1 deletions

diff --git a/TEST_MAPPING b/TEST_MAPPING
index 98c2fc880..742f12eab 100644
--- a/TEST_MAPPING
+++ b/TEST_MAPPING
@@ -1,7 +1,8 @@
 {
   "postsubmit": [
     {
-      "name": "DocumentsUIGoogleTests"
+      "name": "DocumentsUIGoogleTests",
+      "keywords": ["primary-device"]
     }
   ]
 }