[SDK-2487] Reverted minimum sdk version change (#1224)

Reverted minimum sdk version change

ChangeLog.md

@@ -1,4 +1,8 @@
 # Branch Android SDK change log
+- v5.12.4
+  * _*Master Release*_ - Sep 30, 2024
+  - Reverted the minimum SDK build version back to 21
+
 - v5.12.3
   * _*Master Release*_ - Sep 25, 2024
   - Fix to properly fetch install referrers when using deferred init in plugins

gradle.properties

@@ -1,5 +1,5 @@
-VERSION_NAME=5.12.3
-VERSION_CODE=051403
+VERSION_NAME=5.12.4
+VERSION_CODE=051404
 GROUP=io.branch.sdk.android
 
 POM_DESCRIPTION=Use the Branch SDK (branch.io) to create and power the links that point back to your apps for all of these things and more. Branch makes it incredibly simple to create powerful deep links that can pass data across app install and open while handling all edge cases (using on desktop vs. mobile vs. already having the app installed, etc). Best of all, it is really simple to start using the links for your own app: only 2 lines of code to register the deep link router and one more line of code to create the links with custom data.
@@ -13,7 +13,7 @@ POM_LICENCE_DIST=repo
 POM_DEVELOPER_ID=branch
 POM_DEVELOPER_NAME=Branch Metrics
 
-ANDROID_BUILD_SDK_VERSION_MINIMUM=23
+ANDROID_BUILD_SDK_VERSION_MINIMUM=21
 ANDROID_BUILD_SDK_VERSION_COMPILE=34
 ANDROID_BUILD_TOOLS_VERSION=34.0.0
 android.useAndroidX=true