Update bat files to not use find_java.bat

find_java.bat is in the deprecated "tools" component and should no
longer be used. Switching to just looking for what's on the path or in
JAVA_HOME, as other tools do.

Bug: 150888434
Test: none
Change-Id: Idec6abc042efc10dffd3cc718b798134954daf58
Merged-In: Idec6abc042efc10dffd3cc718b798134954daf58