[android][expo-facebook] Add CustomTabActivity to AndroidManifest so ChromeTabs Facebook auth works (#6475)
[android][expo-facebook] Add CustomTabActivity to AndroidManifest so ChromeTabs Facebook auth works (#6475)

# Why

May help fix https://github.com/expo/expo/issues/6427 by enabling Custom Tabs for Facebook login.

x-ref `expo-cli` PR: https://github.com/expo/expo-cli/pull/1338

# How

I noticed that:
- the setup instructions for Facebook Login for Android mention to add this activity to `AndroidManifest`
- never have I seen Facebook login in Expo app to use Chrome Tabs

# Test Plan

With a proper scheme added to `AndroidManifest` authenticating with Facebook showed a custom Chrome tab, which, after success, returned to the app.
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