Fix gn flags around check_android_configuration

This cl fixes an issue where it is not possible to build a stable
channel public build without enabling check_android_configuration (due
to gn failure from useless assignments).

Change-Id: I5b2ecf2a9d9529b75383b2a498e4a6240a89c186
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2090139
Auto-Submit: Mohamed Heikal <mheikal@chromium.org>
Commit-Queue: Andrew Grieve <agrieve@chromium.org>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#747818}

chrome/android/BUILD.gn

@@ -2440,9 +2440,11 @@ template("monochrome_or_trichrome_public_bundle_tmpl") {
     if (defined(invoker.verify_android_configuration) &&
         invoker.verify_android_configuration) {
       verify_manifest = true
+      if (check_android_configuration) {
         failed_manifest_expectation_file =
             "monochrome_public_bundle.android_manifest.failed"
       }
+    }
 
     if (!_is_trichrome ||
         !defined(invoker.static_library_synchronized_proguard) ||
@@ -2473,11 +2475,13 @@ template("monochrome_or_trichrome_public_bundle_tmpl") {
       if (defined(invoker.verify_android_configuration) &&
           invoker.verify_android_configuration) {
         verify_proguard_flags = true
+        if (check_android_configuration) {
           failed_proguard_expectation_file =
               "monochrome_public_bundle.proguard_flags.failed"
         }
       }
     }
+  }
 }
 
 # Public webview targets don't work with non-public sdks.