Move instrumentation tests on linux_android_rel_ng src-side.

See https://chromiumcodereview.appspot.com/1676693004/ for fyi example.

The CL to remove these build-side is https://codereview.chromium.org/1679703004.

BUG=525873

Review URL: https://codereview.chromium.org/1672263002

Cr-Commit-Position: refs/heads/master@{#374647}

testing/buildbot/chromium.linux.json

@@ -254,6 +254,20 @@
         "test": "unit_tests"
       }
     ],
+    "instrumentation_tests": [
+      {
+        "test": "AndroidWebViewTest"
+      },
+      {
+        "test": "ChromePublicTest"
+      },
+      {
+        "test": "ContentShellTest"
+      },
+      {
+        "test": "ChromeSyncShellTest"
+      }
+    ],
     "scripts": [
       {
         "name": "webview_licenses",
@@ -379,6 +393,20 @@
         "test": "unit_tests"
       }
     ],
+    "instrumentation_tests": [
+      {
+        "test": "AndroidWebViewTest"
+      },
+      {
+        "test": "ChromePublicTest"
+      },
+      {
+        "test": "ContentShellTest"
+      },
+      {
+        "test": "ChromeSyncShellTest"
+      }
+    ],
     "scripts": [
       {
         "name": "webview_licenses",