Installing the Xperia Keyboard on non-Xperia devices
Post #456
 in the link provided by @beeshyams gives the following download link to the modified Xperia keyboard that can be used with a Huawei phone. 
When clicking on the download link, the download should start, and you simply install it as you would with any other apk package. However, always be careful when installing unauthorized packages. 
I don't know much about how this package is created and drawbacks, bugs, etc., but it works for me without any problems. 

If you had a previous version of Xperia keyboard installed


  delete everything from the previous version! library, dalvik cache, just everything. Its really important.