Open Android Studio, and then update all your build tools, install the SDKs that you need for your device and ensure that have you set ANDROID_HOME env var to the same dir that you have in Android Studio (commonly in /home/you/Android/Sdk), also update react-native-cli node package. Run adb kill-server and adb start-server.
Probably you will have problems with adb version, just change your bin:
sudo cp ~/Android/Sdk/platform-tools/adb /usr/bin/adb
sudo chmod +x /usr/bin/adb
