Handle '&' in DexoptUtils#encodeClassLoader

For system apps, we pass '&' for CLC.
The method was treating this as a path as a result we were getting
wrong encoding for CLC.
This was causing dexopt failures for A/B OTA.

Removed the secondary dex file dexopt till we fixed it.

Bug: 65067046
Test: runtest.py -x \
  frameworks/base/services/tests/servicestests/src/com/android/server/pm/dex/DexoptUtilsTest.java
(cherry-picked from commit 557c0549)
Change-Id: I9aa440750c811676c86d8c6d0d451077d0edf5a0