Steps to reproduce:
1. Open project attached by QA
2. Install 'Google Korean Input'
3. Attempt to enter Korean in any text field
4. Deploy project to device
5. Attempt to enter Korean in Unity text field

Expected behaviour: Entering Korean into text field
Actual behaviour: Latin letters are entered

Reproduced on: 2017.1.0p1, 2017.1.1f1, 2017.2.0b9, 2017.3.0a6
Not reproduced on: 5.6.3p2, 2017.1.0f3
Regression introduced in: 2017.1.0p1

Note: 'Google Japanese Input' works fine

Reproduced on:
Google Nexus 5X*, OS:7.1.2, CPU:arm64-v8a, GPU:Adreno (TM) 418, Build:google/bullhead/bullhead:7.1.2/N2G47W/3938523:user/release-keys
Xiaomi MI 5s*, OS:6.0.1, CPU:arm64-v8a, GPU:Adreno (TM) 530, Build:Xiaomi/capricorn/capricorn:6.0.1/MXB48T/V8.0.10.0.MAGCNDH:user/release-keys

Not reproduced on:
iPod 6th gen, iOS 10.2.1

Fixed in: 2017.3.0b1
Backported to: 2017.1.1p2, 2017.2.0b11