Steps to reproduce:

1) Download attached project and open in Unity
2) Make sure "Predictive text" is enabled in "Language and Input" device settings
3) Build and Run project on device
4) Try to enter any text in any field for example "dont"
Note: text will be autocorrected to "don't"

Expected result: Autocorrection should work only in the second field because type of this field is set to "Autocorrected" (check attached video "expected.mp4")
Actual result: Autocorrection works on most types of the fields ex: "Standard", "Name", "Custom"(default) (check attached video "repro.mp4")

Reproduced with:

5.6.5f1, 2017.1.3f1, 2017.2.1p1, 2017.3.0p1, 2018.1.0b1

Devices under test:
Reproduced with:
0154 || Samsung Galaxy Note 8, OS: 7.1.1, CPU: Samsung Exynos 9 Octa, GPU: Mali-G71
0144 || Samsung Galaxy S8, OS: 7.0, CPU: Exynos 9 Octa, GPU: ARM Mali-G71

Not reproduced with:
0079 || Samsung Galaxy S7, OS: 7.0.1, CPU: Exynos 8 Octa (8890), GPU: ARM Mali-T880