Fix findbugs violations in netconf

Fix findbugs violations in netconf

- Field is a mutable collection which should be package protected
- Unchecked/unconfirmed cast of return value from method
- May expose internal representation by returning reference to mutable object
- May expose internal representation by incorporating reference to mutable object
- Field should be package protected
- Parameter must be non-null but is marked as nullable
- Nullcheck of value previously dereferenced
- Inconsistent synchronization
- Method ignores return value
- Boxing/unboxing to parse a primitive
- Boxed value is unboxed and then immediately reboxed
- Unchecked/unconfirmed cast
- Class implements same interface as superclass
- Switch statement found where one case falls through to the next case
- Field not initialized in constructor but dereferenced without null check
- Reliance on default encoding
- Private method is never called
- Method invokes toString() method on a String
- Possible null pointer dereference
- Consider using Locale parameterized version of invoked method
- Field not guarded against concurrent access
- Method does not release lock on all exception paths
- Inefficient use of keySet iterator instead of entrySet iterator
- Load of known null value
- Redundant nullcheck of value known to be non-null
- Non-transient non-serializable instance field in serializable class
- Class is Externalizable but doesn't define a void constructor
- Class is Serializable, but doesn't define serialVersionUID
- Class defines field that masks a superclass field
- Should be a static inner class
- Repeated conditional tests
- Format string should use %n rather than \n
- Method may fail to close stream
- Unconditional wait
- Wait not in loop
- Method concatenates strings using + in a loop
- Dead store to local variable
- Possible null pointer dereference due to return value of called method
- Useless object created

Change-Id: If4b7fe5431a4b957f344ecc4307982a40241c97b
Signed-off-by: Tom Pantelis <tompantelis@gmail.com>