build: remove credential properties

This commit removes Maven Central credentials and signing key information from the `gradle.properties` file.

Author: nchocha-kairosliving

gradle.properties

@@ -6,10 +6,3 @@ android.uniquePackageNames=false
 android.r8.strictFullModeForKeepRules=false
 android.nonTransitiveRClass=true
 
-mavenCentralUsername=aA2vDwQH
-mavenCentralPassword=QrmuFa42h4kGUyE9chE+ux9jA3AZZ7gBHVIQ0RgpwbZp
-
-signing.keyId=90487542
-#signing.keyId=C7820F55
-signing.password=Naresh@711997
-signing.secretKeyRingFile=../secring.gpg