Update suggested JDK link to OpenJDK (#3500)
Update suggested JDK link to OpenJDK (#3500)

Oracle JDK now requires an Oracle account, OpenJDK is easier to obtain.

b/145703511
google/agi,google/gapid,google/gapid,google/agi,google/gapid,pmuetschard/gapid,pmuetschard/gapid,pmuetschard/gapid,google/gapid,pmuetschard/gapid,google/agi,google/agi,pmuetschard/gapid,google/gapid,google/gapid,google/agi,pmuetschard/gapid,google/agi,google/agi,pmuetschard/gapid,google/gapid,google/agi,pmuetschard/gapid,google/gapid