Move TetheringTests to presubmit

The TetheringTests are green in postsubmit for a while.
Also add TetheringIntegrationTests to postsubmit.

Bug: 148998835
Test: atest --test-mapping frameworks/base/packages/Tethering:postsubmit
      atest --test-mapping frameworks/base/packages/Tethering:presubmit
Change-Id: I80d29d06fde5a718c31a0a5ad2e2562be5bf419f
diff --git a/Tethering/TEST_MAPPING b/Tethering/TEST_MAPPING
index 73254cd..5617b0c 100644
--- a/Tethering/TEST_MAPPING
+++ b/Tethering/TEST_MAPPING
@@ -1,7 +1,12 @@
 {
-  "postsubmit": [
+  "presubmit": [
     {
       "name": "TetheringTests"
     }
+  ],
+  "postsubmit": [
+    {
+      "name": "TetheringIntegrationTests"
+    }
   ]
 }