storage: Don't list removed volumes in storage list

 * Don't tell apps that USB storage or empty SD slots are available for
   use. This fixes errors about trying to create dirs in vold as well
   as the relevant CTS cases.

Change-Id: Ic763d40c19b0bb9f7497cc1515baf1661d76e9ee
Fix a JNI local reference leaks of CallStaticObjectMethod

Change-Id: I98cf300075fb8e8b3fbc532c6e94370542f6fffa
Signed-off-by: You Kim <you.kim72@gmail.com>