fix(android): make readFile don't return newlines on base64 strings

[rosmcmahon]

On Android, the default action of Filesystem.readFile creates a malformed base64 string with newlines added.

This is acceptable in the browser when displaying images, for example, but not when base64 data is expected.

ref [https://developer.android.com/reference/android/util/Base64#NO_WRAP]

[jcesarmobile]

makes sense, we use NO_WRAP on camera plugin and when writing, thanks!