Fix apksigner execution failure on linux

Author: Muller-Castro

platform/android/export/export_plugin.cpp

@@ -2522,6 +2522,13 @@ String EditorExportPlatformAndroid::get_apksigner_path(int p_target_sdk, bool p_
 	String java_sdk_path = EDITOR_GET("export/android/java_sdk_path");
 	if (!java_sdk_path.is_empty()) {
 		OS::get_singleton()->set_environment("JAVA_HOME", java_sdk_path);
+
+#ifdef UNIX_ENABLED
+		String env_path = OS::get_singleton()->get_environment("PATH");
+		if (!env_path.contains(java_sdk_path)) {
+			OS::get_singleton()->set_environment("PATH", java_sdk_path + "/bin:" + env_path);
+		}
+#endif
 	}
 
 	List<String> args;