[tp] specify explicit guava 27.1-jre dependency in parent pom.xml
[tp] specify explicit guava 27.1-jre dependency in parent pom.xml

And leave out the Maven version from the tp (Guava will come from the p2
sites, Xtext, Orbit).
b2ihealthcare/snow-owl,b2ihealthcare/snow-owl,b2ihealthcare/snow-owl,b2ihealthcare/snow-owl