weblayer: makes android bots build run_weblayer_shell

This way we get build bot coverage.

BUG=none
TEST=none

Change-Id: Ibce3b2be48420e70a839545a950d105d956477fe
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1790743Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Commit-Queue: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#695045}

testing/buildbot/gn_isolate_map.pyl

@@ -3001,7 +3001,7 @@
     "type": "console_test_launcher",
   },
   "weblayer_shell": {
-    "label": "//weblayer/shell:weblayer_shell",
+    "label": "//weblayer/shell/android:run_weblayer_shell",
     "type": "additional_compile_target",
   },
   "wm_unittests": {