JAVA: Unified Java Example names

Unified all Java examples to *match* <LIBRARY>[_otherstuf]_Example.java.
Note, a handful of the examples have a pseudo-random string for the
first component (see FlexSensor_Example.java, ideally this would be
Flex_Example.java).

This commit allows for quick development on a single sensor library
since a -DMODULE_LIST=mysensorlib now works with Java examples
(previously Java examples would fail generation when using
MODULE_LIST).

    * Renamed examples
    * Updated class names
    * Updated library descriptor .json files
    * Updated sample mapping file

TODO: Make this work like the C/C++ examples - grab the target library
name from the filename and grab all dependencies from that target
library.  Fix the handful of example names which don't conform.

Signed-off-by: Noel Eck <noel.eck@intel.com>

src/mhz16/mhz16.json

@@ -12,7 +12,7 @@
             "Manufacturers": ["Seeed", "Zhengzhou Winsen Electronics Technology"],
             "Image": "mhz16.jpg",
             "Examples": {
-                "Java" : ["MHZ16Sample.java"],
+                "Java" : ["MHZ16_Example.java"],
                 "Python": ["mhz16.py"],
                 "Node.js": ["mhz16.js"],
                 "C++": ["mhz16.cxx"]