Make some of the c.g.g.view.client.*SelectionModelTest tests async. - #10365

[checkstyle] reported by reviewdog 🐶 Line matches the illegal pattern 'more than one blank line'. Raw Output: /home/runner/work/gwt/gwt/gwt/user/test/com/google/gwt/view/client/MultiSelectionModelTest.java:16:0: info: Line matches the illegal pattern 'more than one blank line'. (com.puppycrawl.tools.checkstyle.checks.regexp.RegexpCheck)

[checkstyle] reported by reviewdog 🐶 Line matches the illegal pattern 'more than one blank line'. Raw Output: /home/runner/work/gwt/gwt/gwt/user/test/com/google/gwt/view/client/DefaultSelectionModelTest.java:16:0: info: Line matches the illegal pattern 'more than one blank line'. (com.puppycrawl.tools.checkstyle.checks.regexp.RegexpCheck)

[removal] Double(double) in Double has been deprecated and marked for removal

[removal] Double(double) in Double has been deprecated and marked for removal

[removal] Double(double) in Double has been deprecated and marked for removal

[removal] Double(double) in Double has been deprecated and marked for removal

[LongDoubleConversion] Conversion from long to double may lose precision; use an explicit cast to double if this was intentional

[AlmostJavadoc] This comment contains Javadoc or HTML tags, but isn't started with a double asterisk (/**); is it meant to be Javadoc?

[EffectivelyPrivate] This declaration has public or protected modifiers, but is effectively private.

[EffectivelyPrivate] This declaration has public or protected modifiers, but is effectively private.

[CatchAndPrintStackTrace] Logging or rethrowing exceptions should usually be preferred to catching and calling printStackTrace