put this at the top of your main module
#CustomBuildAction: folders ready, %WINDIR%\System32\Robocopy.exe,/S "..\..\Android Specific" ".."
#CustomBuildAction: folders ready, %WINDIR%\System32\Robocopy.exe,/S "..\..\Android Specific" ".."
and put icon.png in
project folder \Android Specific\Objects\res\drawable\
then you just need to update your icon in the Android specific folder and it gets copied at compile so it won't get lost during a manual clean of the objects folder.
my project folder structure is as follows...
Android Specific\
B4A\
B4i\
B4J\
Data\
IOS Specific\
Shared Files\
Shared Modules\