fix(launcher): output correct error message for browser (#6815)

* fix(launcher): output correct error message for browser

When running `npm run release` today I got this error logged:

```
Error: Could not find browser revision 848005. Run "PUPPETEER_PRODUCT=firefox npm install" or "PUPPETEER_PRODUCT=firefox yarn install" to download a supported Firefox browser binary.
    at ChromeLauncher.launch (/Users/jacktfranklin/src/puppeteer/lib/cjs/puppeteer/node/Launcher.js:80:27)
```

The error is only partially correct; I did have the browser revision
missing, but I needed the Chromium browser, not Firefox. It turns out
the logic in `Launcher.ts` didn't take this into account; it mistakenly
had been hardcoded to always log out the error as if the Firefox binary
was missing.

This PR updates the message depending on the browser:

Chrome error:
> Error: Could not find expected browser (chrome) locally. Run npm
> install or yarn install to download the correct Chromium revision
> (848005).

Firefox error:
> Error: Could not find expected browser (firefox) locally. Run
> "PUPPETEER_PRODUCT=firefox npm install" or "PUPPETEER_PRODUCT=firefox
> yarn install" to download a supported Firefox browser binary.

* Update src/node/Launcher.ts

Co-authored-by: Mathias Bynens <mathias@qiwi.be>

Co-authored-by: Mathias Bynens <mathias@qiwi.be>

src/node/Launcher.ts

@@ -615,6 +615,7 @@ function resolveExecutablePath(
     product: launcher.product,
     path: downloadPath,
   });
+
   if (!launcher._isPuppeteerCore && launcher.product === 'chrome') {
     const revision = process.env['PUPPETEER_CHROMIUM_REVISION'];
     if (revision) {
@@ -627,8 +628,13 @@ function resolveExecutablePath(
     }
   }
   const revisionInfo = browserFetcher.revisionInfo(launcher._preferredRevision);
+
+  const firefoxHelp = `Run \`PUPPETEER_PRODUCT=firefox npm install\` to download a supported Firefox browser binary.`;
+  const chromeHelp = `Run \`npm install\` to download the correct Chromium revision (${launcher._preferredRevision}).`;
   const missingText = !revisionInfo.local
-    ? `Could not find browser revision ${launcher._preferredRevision}. Run "PUPPETEER_PRODUCT=firefox npm install" or "PUPPETEER_PRODUCT=firefox yarn install" to download a supported Firefox browser binary.`
+    ? `Could not find expected browser (${launcher.product}) locally. ${
+        launcher.product === 'chrome' ? chromeHelp : firefoxHelp
+      }`
     : null;
   return { executablePath: revisionInfo.executablePath, missingText };
 }