Fix jacoco_cli invocation

jacoco_cli --dest takes a directory, not a jar name, and assumes
an output file with the same name as the input jar in that
directory.  Rename jacoco-report-classes.jar to
jacoco-report-classes/modulename.jar, and generate to
jacoco/tmp/modulename.jar before combining to the final output file
at jacoco/modulename.jar.

Bug: 69669951
Test: m EMMA_INSTRUMENT=true
Change-Id: Ia7dd881d2819ae09dfb60a00b4c1b8396629cd9a