build: switch to Maven configuration for JavaIndexer

java_indexer/src/main/java/com/sourcetrail/DefinitionKind.java

@@ -0,0 +1,20 @@
+package com.sourcetrail;
+
+public enum DefinitionKind
+{ // these values need to be the same as DefinitionKind in C++ code
+	NONE(0),
+	IMPLICIT(1),
+	EXPLICIT(2);
+	
+	private final int m_value;
+	
+    private DefinitionKind(int value) 
+    {
+        this.m_value = value;
+    }
+
+    public int getValue() 
+    {
+        return m_value;
+    }
+}