ci: align Githug-Android workflow with Android release pattern

app/build.gradle.kts

@@ -1,10 +1,16 @@
 import java.util.Properties
 
-val keystoreProperties = Properties()
 val keystorePropertiesFile = rootProject.file("keystore.properties")
+val keystoreProperties = Properties()
 if (keystorePropertiesFile.exists()) {
     keystorePropertiesFile.inputStream().use { keystoreProperties.load(it) }
 }
+val hasReleaseSigning = listOf(
+    "storeFile",
+    "storePassword",
+    "keyAlias",
+    "keyPassword",
+).all { !keystoreProperties.getProperty(it).isNullOrBlank() }
 
 plugins {
     id("com.android.application")
@@ -34,9 +40,9 @@ android {
     }
 
     signingConfigs {
-        if (keystorePropertiesFile.exists()) {
+        if (hasReleaseSigning) {
             create("release") {
-                storeFile = file(keystoreProperties.getProperty("storeFile"))
+                storeFile = rootProject.file(keystoreProperties.getProperty("storeFile"))
                 storePassword = keystoreProperties.getProperty("storePassword")
                 keyAlias = keystoreProperties.getProperty("keyAlias")
                 keyPassword = keystoreProperties.getProperty("keyPassword")
@@ -45,9 +51,11 @@ android {
     }
 
     buildTypes {
+        debug {
+        }
         release {
             isMinifyEnabled = false
-            if (signingConfigs.findByName("release") != null) {
+            if (hasReleaseSigning) {
                 signingConfig = signingConfigs.getByName("release")
             }
             proguardFiles(