Bug 1742823, handle pdf in this test when improvements pref is either on or off, r=mtigley

Differential Revision: https://phabricator.services.mozilla.com/D132044

uriloader/exthandler/tests/mochitest/browser_extension_correction.js

@@ -63,7 +63,7 @@ async function checkDownloadWithExtensionState(
 
   // PDF should load using the internal viewer without downloading it.
   let waitForLoad;
-  if (type == "application/pdf") {
+  if (!shouldExpectDialog && type == "application/pdf") {
     waitForLoad = BrowserTestUtils.browserLoaded(gBrowser.selectedBrowser);
   }
 
@@ -101,7 +101,7 @@ async function checkDownloadWithExtensionState(
     dialog.acceptDialog();
   }
 
-  if (type == "application/pdf") {
+  if (!shouldExpectDialog && type == "application/pdf") {
     is(
       gURLBar.inputField.value,
       "data:application/pdf,hello",