makebuildserver: update platform and build tool releases
makebuildserver: update platform and build tool releases

Update platform-25 to r03
Update platform-26 to r02
Add build-tools_r26.0.1

sha256 signatures locally computed after verifying the sha1 signature provided
by the repository2-1.xml file.

All these will be downloaded and installed in the buildserver through
provision-android-sdk anyway but this adds them to the cache.

fdroidtravis/fdroidserver,f-droid/fdroid-server,fdroidtravis/fdroidserver,f-droid/fdroidserver,f-droid/fdroid-server,f-droid/fdroid-server,f-droid/fdroidserver,f-droid/fdroid-server,f-droid/fdroid-server,f-droid/fdroidserver,f-droid/fdroidserver,f-droid/fdroidserver,fdroidtravis/fdroidserver,fdroidtravis/fdroidserver