Providing another ways to do the authentication without firebase

[nileshrkdf]

Please execute this shell command then replace it with your console output.

echo ''
echo "### OS"
sw_vers 
echo '### POD'
pod --version
echo "### Project"
git ls-tree --full-name --name-only HEAD Podfile
pwd
echo '

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Problem | Feature

HI Team,

I wanted to modify the code so that it should also consider authenticating/getting token via ServiceAccountTokenProvider and bypass the firebase, so that we don't have to setup firebase to enable this .

I am attaching the updated files you guys can review it and if you find it ok then you can consider this changes.

Thanks, Changes.zip