chore: Update version to 0.8.7-alpha (master)

Updates the application version to 0.8.7-alpha.
Includes a changelog entry for bug fixes and stability improvements.

Affected files:
- app/build.gradle.kts
- fastlane/metadata/android/en-US/changelogs/87.txt

Author: JackEblan

app/build.gradle.kts

@@ -26,8 +26,8 @@ android {
 
     defaultConfig {
         applicationId = "com.eblan.launcher"
-        versionCode = 86
-        versionName = "0.8.6-alpha"
+        versionCode = 87
+        versionName = "0.8.7-alpha"
 
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
     }

fastlane/metadata/android/en-US/changelogs/87.txt

@@ -0,0 +1 @@
+- Bug fixes and stability improvements