Fixed some build errors when compiling after cleanup
ex) warning: [NoSynchronizedMethodCheck] Used synchronized modifier in public method
warning: [NoRedundantFieldInit] Do not explicitly initialize a non-final field with a default value
warning: unused member
Fixed some build errors when compiling after cleanup ex) warning: [NoSynchronizedMethodCheck] Used synchronized modifier in public method warning: [NoRedundantFieldInit] Do not explicitly initialize a non-final field with a default value warning: unused member