Refactor FieldImage tests to use dev-tools helpers (#4315)
Refactor FieldImage tests to use dev-tools helpers (#4315)

* Refactor FieldImage tests to use dev-tools helpers
rachel-fenichel/blockly,google/blockly,google/blockly,google/blockly,mark-friedman/blockly,google/blockly,mark-friedman/blockly,rachel-fenichel/blockly,rachel-fenichel/blockly,rachel-fenichel/blockly,google/blockly,mark-friedman/blockly,google/blockly,mark-friedman/blockly,mark-friedman/blockly,rachel-fenichel/blockly,rachel-fenichel/blockly,mark-friedman/blockly,rachel-fenichel/blockly,google/blockly