Check for null in LocalSocketImpl.SocketInputStream.available()

Calling available() on a local socket after close() will cause a native
crash. Other methods that pass LocalSocketImpl.fd to native code copy
the fd and check for null.

Change-Id: I2d0b573f34ae47a23009760bbb1c02933ab0a20e
Fix NullException in QwertyKeyListener.KeyDown

Extending null protection for view to "c == i" case in addition to
"c == Character.toUpperCase(i)" case that helped to fix some force closures.
Seems as typo in original implementation.

Change-Id: Ibaa5aea95c5c8cdc8ac981fe0d1dad313e3e692f
Signed-off-by: Dmitry Tsyganyuk <fdt017@motorola.com>