Android build: Add cleanup for installed headers.

Makefile

@@ -54,6 +54,7 @@ clean:
 	$(MAKE) -C db clean
 	$(MAKE) -C asn.1 clean
 	$(MAKE) -C sync clean
+	$(MAKE) -C build-android clean
 
 tags:
 	$(MAKE) -C asn.1 tags

build-android/Makefile

@@ -0,0 +1,13 @@
+# Copyright 2020, pEp Foundation
+# This file is part of pEpEngine - Android Build
+# This file may be used under the terms of the GNU General Public License version 3
+# see LICENSE.txt
+
+include ../Makefile.conf
+
+all:
+	echo "Placeholder command, this is meant to be cleaned by JNIAdapter Android build"
+
+.PHONY: clean
+clean:
+	rm -rf include/