[Feature] Apply better-regex lint fixes

[ConnorQi01]

Summary

Apply the existing unicorn/better-regex recommendations to two validation regular expressions while preserving their current behavior.

Why this is useful

The current expressions are correct but use verbose character ranges and an unnecessary escaped slash. Simplifying them removes lint warnings and keeps the validation intent easier to read.

Proposed Changes

• Simplify the filepath validation character class in src/extension/android/androidContainerUtility.ts.
• Simplify the version validation digit classes in src/extension/commands/installExpoGoApplication.ts.
• Keep the accepted and rejected input behavior unchanged.

Validation

• Run Prettier checks for both modified files.
• Run npm run build.
• Run the relevant tests or the full npm test suite.