#SDK exporting - this will solve your issue
export ANDROID_HOME=/home/{user}/Android/Sdk 

#Tools exporting - it can be need in your case
export PATH=/home/{user}/Android/Sdk/platform-tools:$PATH
export PATH=/home/{user}/Android/Sdk/tools:$PATH
export PATH=/home/{user}/Android/ndk-build:$PATH

#Flutter binary exporting
export PATH=/home/{user}/flutter/bin:$PATH