IOT-2533 Build java with scons

IOT-2533 Build java with scons

When building generic_java stop using gradle.
Gradle is required to build aar and apk files
for android but scons is capable of building
the java code without using gradle.

This also has the side effect that we can add
a more complete manifest file that makes running
the samples simpler. We no longer need to run
long commandline java commands to start the
samples.

example:
cd <ouput_dir>/java
java -Djava.library.path=.. -jar simplerserver.jar

See IOT-2419 for SECURED=1 build
Bug: Bug: https://jira.iotivity.org/browse/IOT-2419

Bug: https://jira.iotivity.org/browse/IOT-2533
Change-Id: I8bf5228173745d26114e612a0d82d1f28060d801
Signed-off-by: George Nash <george.nash@intel.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/21965
Tested-by: jenkins-iotivity <jenkins@iotivity.org>
Reviewed-by: Larry Sachs <larry.j.sachs@intel.com>
Reviewed-by: Rick Bell <richard.s.bell@intel.com>