Release v7.7.1

[isouravganguly]

Summary

• expose launchScWebView for webview-as-a-service
• update Android SCGateway to 6.1.3
• update iOS SCGateway to 7.2.1
• retain iOS SCLoans 7.4.0
• update the sample app and public repository documentation

Validation

• TypeScript validation passed
• Android and iOS sample builds passed
• launchScWebView focused test passed before the production backmerge

Release

• package version: 7.7.1
• tag: v7.7.1