Reproduction steps:
1) Open any project or create a new one
2) Set up keystore.
3) Set up Alias with a name like " !@#$%^&*()_+ты\[супэр}'žvaigždė{ " or " as’asda”asd’asda’”’ "
4) Try building for Android device with Gradle build system

Expected: build succeeds
Actual: Errors are thrown

Reproduced on: 2017.4.11f1, 2018.1.9f2, 2018.2.7f1, 2018.3.0b1
and
Version 2019.1.0a1 (a95a274daf4f)
Sat, 08 Sep 2018 11:49:49 GMT
Branch: trunk

"'C:\Unity_Projects\Android_Multicast_Repro\Temp\gradleOut\build.gradle': 63: unexpected char: '\' @ line 63, column 37.
keyAlias '!@#$%^&*()_+??\[?????}'�vaig�d?{ '"
or
"A problem occurred evaluating root project 'gradleOut'.
> Cannot invoke method asda() on null object
"