Bump mockitoVersion from 3.5.13 to 3.5.15

Bumps `mockitoVersion` from 3.5.13 to 3.5.15.

Updates `mockito-core` from 3.5.13 to 3.5.15
- [Release notes](https://github.com/mockito/mockito/releases)
- [Commits](https://github.com/mockito/mockito/compare/v3.5.13...v3.5.15)

Updates `mockito-android` from 3.5.13 to 3.5.15
- [Release notes](https://github.com/mockito/mockito/releases)
- [Commits](https://github.com/mockito/mockito/compare/v3.5.13...v3.5.15)

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

build.gradle

@@ -61,7 +61,7 @@ ext {
     prismVersion = "2.0.0"
     butterknifeVersion = "10.2.3"
     androidLibraryVersion = "master-SNAPSHOT"
-    mockitoVersion = "3.5.13"
+    mockitoVersion = "3.5.15"
     mockkVersion = "1.10.2"
     byteBuddyVersion = "1.10.17"
     espressoVersion = "3.3.0"