Respect ios_automatically_manage_certs when building EG tests.

ios/chrome/test/earl_grey/chrome_ios_eg_test.gni

Index: ios/chrome/test/earl_grey/chrome_ios_eg_test.gni
diff --git a/ios/chrome/test/earl_grey/chrome_ios_eg_test.gni b/ios/chrome/test/earl_grey/chrome_ios_eg_test.gni
index 9e55660fb998e8f58a545570c60bfa8621e34ca5..78cbc4ad3d0922b6e6c41b8827e23881d04b55ef 100644
--- a/ios/chrome/test/earl_grey/chrome_ios_eg_test.gni
+++ b/ios/chrome/test/earl_grey/chrome_ios_eg_test.gni
@@ -130,7 +130,6 @@ template("chrome_ios_eg_test") {
       extra_substitutions = []
     }
     extra_substitutions += [
-      "CHROMIUM_BUNDLE_ID=gtest.$target_name",
       "CHROMIUM_HANDOFF_ID=$chromium_handoff_id",
       "CHROMIUM_SHORT_NAME=$target_name",
       "CHROMIUM_URL_SCHEME_1=$url_unsecure_scheme",
@@ -140,5 +139,12 @@ template("chrome_ios_eg_test") {
       "EG_MAIN_APPLICATION_DELEGATE=$_eg_main_application_delegate",
       "SSOAUTH_URL_SCHEME=$url_ssoauth_scheme",
     ]
+    if (ios_automatically_manage_certs) {
+      # Use the same bundle identifier for EarlGrey tests as for unit tests
+      # when managing certificates as the number of free certs is limited.
+      extra_substitutions += [ "CHROMIUM_BUNDLE_ID=gtest.generic-unit-test" ]
+    } else {
+      extra_substitutions += [ "CHROMIUM_BUNDLE_ID=gtest.$target_name" ]
+    }
   }
 }