SDK: Fixed proguard.bat & co.

These are similar to the external/proguard/bin/*.bat
except they use $SDK/tools/lib/find_java.bat to locate the
java location and use it if available. find_java will print
a proeminent error if java cannot be found.

Change-Id: I1fceae838436053031f405de9b3f1ab2d64222e6
3 files changed