Down integrate Google3 changes to Github

Installing BOM before running Java test

Add com.google.truth as test dependencies

This goes hand-in-hand with other dependencies like junit, but seems to
only have been used from util/pom.xml.

Add length checks to ExtensionCollection

c# feature(RepeatedField): Capacity property to resize the internal array

Remove unused argument to avoid UB

This fixes build on, at least, NetBSD 8.1 with gcc 5.5 and SmartOS with gcc 7.

Java: Update to Guava 28.1-android

Fixed bug in Ruby DSL when no names are defined in a file.

Ported names fix for Ruby to the release branch.

`OneOfDescriptor_each` is registered as a Ruby method which takes zero
parameters, which means it should take one argument.

When Ruby invokes `OneOfDescriptor_each`, it calls it with one parameter
only, which is one less than what `OneOfDescriptor_each` takes before
this commit. Calling a function with the wrong number of argument is
technically undefined behavior.

See also: §6.5.2.2, N1256

Merge 3.10.x with master and increment the version number

* Fix conformance test

Default value of string/message map is not encoded

* Fix zts build

Update CHANGES.txt with changes since 3.10.0-RC1

* Initialize well known type values

Also fixes #6667

* Revert unwanted change

* Initialize well known type values

Also fixes #6667

* Revert unwanted change