change test mapping group name

change group name from `auto-postsubmit` to `auto-end-to-end-postsubmit`

Test: run atest :auto-end-to-end-postsubmit
Change-Id: Ibf664eec813dc080b905adb5f5a806ed8242185c
diff --git a/packages/CarSystemUI/src/com/android/systemui/TEST_MAPPING b/packages/CarSystemUI/src/com/android/systemui/TEST_MAPPING
index f90947c..f2bf811 100644
--- a/packages/CarSystemUI/src/com/android/systemui/TEST_MAPPING
+++ b/packages/CarSystemUI/src/com/android/systemui/TEST_MAPPING
@@ -1,5 +1,5 @@
 {
-  "auto-postsubmit": [
+  "auto-end-to-end-postsubmit": [
     {
       "name": "AndroidAutoUiTests",
       "options" : [