MtpDatabase JNI: Fixed a memory-leak in getObjectPropertyValue().

The jstring "stringValue" was not never freed.
In the case where "str" was NULL the whole cleanup part (see "goto out")
was even skipped.
This patch makes getObjectPropertyValue() behave like
getObjectPropertyList().

Change-Id: I5a7ec3611036f5253a054b00064999bcd1d1c29e
Keyguard: fix NPE setting lockscreen wallpaper

After boot the view might not be laid out and so getWidth() and
getHeight() return 0 and will cause a NullPointerException in
createBitmap().

Change-Id: Ibacf4199a69709dc34d21695732c2a5360533a23
Signed-off-by: Dirk Rettschlag <dirk.rettschlag@gmail.com>