fix: update BrowserStack environment variable instructions for consistency

Author: ruturaj-browserstack

src/tools/sdk-utils/constants.ts

@@ -277,14 +277,14 @@ Export your BrowserStack username and access key as environment variables.
 
 For macOS/Linux:
 \`\`\`bash
-export BROWSERSTACK_USERNAME="YOUR_USERNAME"
-export BROWSERSTACK_ACCESS_KEY="YOUR_ACCESS_KEY"
+export BROWSERSTACK_USERNAME= ${config.browserstackUsername}
+export BROWSERSTACK_ACCESS_KEY= ${config.browserstackAccessKey}
 \`\`\`
 
 For Windows PowerShell:
 \`\`\`powershell
-$env:BROWSERSTACK_USERNAME="YOUR_USERNAME"
-$env:BROWSERSTACK_ACCESS_KEY="YOUR_ACCESS_KEY"
+$env:BROWSERSTACK_USERNAME=${config.browserstackUsername}
+$env:BROWSERSTACK_ACCESS_KEY=${config.browserstackAccessKey}
 \`\`\`
 
 **2. Install the BrowserStack WDIO Service**

src/tools/sdk-utils/percy/constants.ts

@@ -166,7 +166,7 @@ export const PERCY_INSTRUCTIONS: PercyConfigMapping = {
       },
       webdriverio: {
         script_updates: webdriverioPercyInstructions,
-      }
+      },
     },
   },
 };