[Java] Use android platform level 26, android platform version 8.0.0_r2
[Java] Use android platform level 26, android platform version 8.0.0_r2

Change-Id: Ic966adb1666130721bcddf5de32b1b7d01fc1e5c

bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr