Add gradle --configure-on-demand flag to bintray upload script

Gradle by default configures all projects, even the ones which will not be executed. Because of this, it always asks for the keystore passwords for the demo app, which is a PITA. Adding this flag makes the bintray upload script run without user interaction.

bintrayupload.bat

@@ -8,5 +8,5 @@ SET apikey=%2
 SET modules="MediaPlayer" "MediaPlayer-DASH"
 
 FOR %%m in (%modules%) DO (
-	gradlew %%~m:clean %%~m:build %%~m:bintrayUpload -PbintrayUser=%username% -PbintrayKey=%apikey% -PdryRun=false
+	gradlew %%~m:clean %%~m:build %%~m:bintrayUpload -PbintrayUser=%username% -PbintrayKey=%apikey% -PdryRun=false --configure-on-demand
 )