With a friend we were a long time trying to work with Git and Android Studio, but we had a problem (we are very new to git and Android Studio, we started a couple of days ago on
Followed by @Akhil's answer, click "Make Project" icon to awake your Run
button. Sometimes this button makes Android Studio recognize your project runnable again.
This is because you have added .idea folder in your git repository.Sample .gitignore file can be like this
build/
.gradle/
*.iml
.idea/
src/main/gen/*
*~
*.swp
local.properties
*.keystore
*.keystore.password
Also you need to delete this folder from git repo. You can use below command
git rm -rf .idea/
git commit -m "deleting .idea, updated .gitignore"
Then try to merge