Added Google Auth

[Abh1shekSingh]

Explanation

Added Google Authentication using Firebase. Which is also Responsive, and not breaking the production

Type of Change:

• Code

Checklist

• The PR title starts with "Fix #bugnum: "followed by a short, clear summary of the changes. ( If this PR fixes part of an issue, prefix the title with "Fix part of #bugnum: I will Add Google authentication #96 ")
• The PR explanation includes the words "Fixes #bugnum: I will Add Google authentication #96 " ( or "Fixes part of #bugnum" if the PR only partially fixes an issue ).
• The PR does not contain any unnecessary auto-generated code from Android Studio.
• The PR does not break any part of the existing code.
• The PR creator have carefully read & adhere to the contributing guidelines of the project.
• The PR is raised for an issue that has been assigned to you.
• The PR is made to the branch that's called "develop".
• The PR is raised from a branch that is up-to-date with "develop".
  
  
  

[Abh1shekSingh]

@riturajjain2000 Please review the code. I have done the required changes

[Abh1shekSingh]

@riturajjain2000 pleas please review