Well the errors you shared are just warning which can be ignored .
the main error is something else here .
Most common error is exit code 1 .
I would need full details of the errors that appear after you run" ionic cordova build android " command .
Also try this solution meanwhile .
goto your ionic project and then first remove :
cordova plugin rm cordova-plugin-facebook4
then add :
ionic cordova plugin add [email protected] --variable APP_ID= --variable APP_NAME=
.