Moving keystore to system/security

keystore used to be in frameworks/base/cmds/keystore, but this include
needs to be changed to support the move to system/security

Change-Id: I583a193593576c2c3c7489fb8c27a29698e8a4c5
Fix INCLUDES path for keystore headers.

Fix the following build error for master:
external/wpa_supplicant_8/hostapd/src/crypto/tls_openssl.c:49:35: fatal error: keystore/keystore_get.h: No such file or directory

Change-Id: I81c64677040287438e467f887c2f1c63a3239350
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>