Fix crash regression when using ANDROID_DEPLOYMENT_DEPENDENCIES

Change 919d07e6

 introduced a
splitRef() on a temporary string, which will cause dangling pointers
as documented. This caused crashes for everyone using
ANDROID_DEPLOYMENT_DEPENDENCIES.

[ChangeLog][androiddeployqt] Fixed a crash when using
ANDROID_DEPLOYMENT_DEPENDENCIES to specify the files to deploy.

Task-number: QTBUG-61636
Change-Id: I16dc84f76667e9b8af5edf79d7c6498657176247
Reviewed-by: BogDan Vatra <bogdan@kdab.com>