Removed unused API which is not support on cordova-android 4.0.0
Removed unused API which is not support on cordova-android 4.0.0

solderzzc/cordova-plugin-file-transfer,FrankSunnyvale/cordova-plugin-file-transfer,solderzzc/cordova-plugin-file-transfer,FrankSunnyvale/cordova-plugin-file-transfer,FrankSunnyvale/cordova-plugin-file-transfer,FrankSunnyvale/cordova-plugin-file-transfer,solderzzc/cordova-plugin-file-transfer,solderzzc/cordova-plugin-file-transfer