Fix sky_tool's installing of SkyShell.apk
Fix sky_tool's installing of SkyShell.apk

We were walking over to the realdir too quickly, which meant we lost which
version of the sky_engine package we were supposed to use.

cbracken/flutter,flutter/flutter,jason-simmons/flutter,cbracken/flutter,Hixie/flutter,jason-simmons/flutter,aghassemi/flutter,cbracken/flutter,turnidge/flutter,tvolkert/flutter,flutter/flutter,flutter/flutter,tvolkert/flutter,Hixie/flutter,turnidge/flutter,flutter/flutter,turnidge/flutter,aghassemi/flutter,aghassemi/flutter,flutter/flutter,tvolkert/flutter,flutter/flutter,flutter/flutter,tvolkert/flutter,tvolkert/flutter,flutter/flutter,flutter/flutter,jason-simmons/flutter,Hixie/flutter,Hixie/flutter,cbracken/flutter,flutter/flutter,tvolkert/flutter,tvolkert/flutter,tvolkert/flutter,jason-simmons/flutter,Hixie/flutter,cbracken/flutter,Hixie/flutter,cbracken/flutter,turnidge/flutter,Hixie/flutter,Hixie/flutter,tvolkert/flutter,Hixie/flutter,cbracken/flutter,Hixie/flutter,cbracken/flutter,aghassemi/flutter,cbracken/flutter,cbracken/flutter,tvolkert/flutter,turnidge/flutter