* Add support for software text editing controls

Includes selection, copy, cut, paste, as well as partial support for up
and down movement.

Text editing controls can be accessed in GBoard by:
  top-left arrow > three dots menu > text editing

Partial fix for flutter/flutter#9419 and flutter/flutter#37371.

* Introduce InputConnectionAdaptor tests

Run with:
  testing/run_tests.py --type=java --java-filter=io.flutter.plugin.editing.InputConnectionAdaptorTest

* Fix BUILD.gn comment on run_tests.py --java-filter flag

…ation fails. Further enforce the same access threshold on layers as on Pictures. Previously layers would always be cached. The latter is a semantic change. (#16545)

If Rasterization fails, i.e. image.is_valid() is false, the cache might try rasterizing the image again on the next frame. Not only is this wasteful put might also prevent other pictures to be cached within the current frame budget.

* script for fetching correct flutter version

* change cirrus yml for the script location

* change location of the script. Add it to tools

* cirrus still does not see the script. repeat path change from the previous step

* Looks like script worked correctly. do not change directory.

* change directory back to build root after scriot is run

* script runs ok. Still not able to find the bin directory. go all the way back

* still can't see the bin directory. carry the script content to cirrus.yml to debug better

* get the last commit id of the right repository

* content of the script worked in cirrus. call the script from tools

* cannot find the script under tools

* print the current path in the script to see why cirrus cannot see bin directory

* move to flutter path before running update packages

* tests run now. remove print outs

* error if the ENGINE_PATH is not set. exit the script

* addressing reviewer comments

* engine branch name on cirrus logs doesn't make sense

* fix typo

* change the directory of branch calculation

* remove extra logs

* addressing PR comments. Testing CIRRUS_CI env variable

* adding CIRRUS_CI check