chore(android): increase minSdkVersion and targetSdkVersion to 26

- Update minSdkVersion from 24 to 26 to support newer Android features
- Update targetSdkVersion from 24 to 26 for compatibility with recent APIs

Author: EndyKaufman

mobile/android/variables.gradle

@@ -1,7 +1,7 @@
 ext {
-    minSdkVersion = 24
+    minSdkVersion = 26
     compileSdkVersion = 35
-    targetSdkVersion = 24
+    targetSdkVersion = 26
     androidxActivityVersion = '1.9.2'
     androidxAppCompatVersion = '1.7.0'
     androidxCoordinatorLayoutVersion = '1.2.0'