Bump gradle from 1.24.4 to 1.25.4 (#1006)

Bumps gradle from 1.24.4 to 1.25.4.

Signed-off-by: dependabot[bot] <support@dependabot.com>

mobile/build.gradle

@@ -10,7 +10,7 @@ buildscript {
     }
     dependencies {
         classpath 'com.google.gms:google-services:3.1.0'
-        classpath 'io.fabric.tools:gradle:1.24.4'
+        classpath 'io.fabric.tools:gradle:1.25.4'
         classpath files('libs/gradle-witness.jar')
     }
 }