test: add util tests

app/build.gradle.kts

@@ -43,11 +43,8 @@ android {
             localeFilters += setOf("en", "es", "eu")
         }
         testInstrumentationRunner = "androidx.benchmark.junit4.AndroidBenchmarkRunner"
-        testInstrumentationRunnerArguments["androidx.benchmark.suppressErrors"] = "ACTIVITY-MISSING"
     }
 
-    testBuildType = "benchmark"
-
     signingConfigs {
         create("release") {
             storeFile = file(localProps["KEYSTORE_PATH"] as String)
@@ -92,6 +89,10 @@ android {
         getByName("debug") {
             java.directories.add("build/generated/ksp/debug/kotlin")
         }
+        getByName("test") {
+            java.srcDirs("src/test/java")
+            kotlin.srcDirs("src/test/java")
+        }
         getByName("release") {
             java.directories.add("build/generated/ksp/release/kotlin")
         }
@@ -122,6 +123,8 @@ dependencies {
     implementation(libs.androidx.material3)
     implementation(libs.androidx.ui)
     testImplementation(libs.junit)
+    testImplementation(libs.kotlin.test)
+    testImplementation(libs.mockk)
     androidTestImplementation(platform(libs.androidx.compose.bom))
     androidTestImplementation(libs.androidx.compose.ui.test.junit4)
     androidTestImplementation(libs.androidx.benchmark.junit4)
@@ -181,6 +184,7 @@ dependencies {
 
     // secp256k1
     implementation(libs.secp256k1.kmp.android)
+    testImplementation(libs.secp256k1.kmp.jvm)
 
     // lyricist
     implementation(libs.lyricist)
@@ -193,6 +197,8 @@ dependencies {
 
     // leakcanary
     debugImplementation(libs.leakcanary.android)
+
+    testImplementation("org.json:json:20240303")
 }
 
 protobuf {