Use com.google.guava:guava:27.0.1-android

- https://stackoverflow.com/questions/52979664/how-to-remedy-error-caused-by-guava-program-type-already-present-com-google-co
- tranleduy2000/ncalc#61

symja_android_library/pom.xml

@@ -73,7 +73,7 @@
 			<dependency>
 				<groupId>com.google.guava</groupId>
 				<artifactId>guava</artifactId>
-				<version>27.0-android</version>
+				<version>27.0.1-android</version>
 			</dependency>
 			<dependency>
 				<groupId>org.apache.logging.log4j</groupId>