Fix "Requires a newer version of Android Auto" prompt (#3491)

Author: DaVinci9196

play-services-core/src/main/kotlin/org/microg/gms/phenotype/PhenotypeService.kt

@@ -90,6 +90,12 @@ private val CONFIGURATION_OPTIONS = mapOf(
     "com.google.android.apps.photos" to arrayOf(
         Flag("45617431", true, 0),
     ),
+    // Android Auto (Gearhead) — lift Car App Library API max for third-party apps.
+    // Without this, AA falls back to baked-in default "DEFAULT:7, gearhead:8" which
+    // blocks Spotify / YouTube Music (require minCarAppApiLevel=8).
+    "com.google.android.projection.gearhead" to arrayOf(
+        Flag("Watevra__host_max_api_level", encodeRepeatedString(listOf("DEFAULT:8")), 0),
+    ),
     "com.google.android.apps.translate" to arrayOf(
         // Enable Practice Tab
         Flag("SpeakEasy__enabled", true, 0),

play-services-core/src/main/kotlin/org/microg/gms/phenotype/extensions.kt

@@ -21,6 +21,22 @@ fun encodeSupportedLanguageList(): ByteArray {
     }.toByteArray()
 }
 
+fun encodeRepeatedString(entries: List<String>): ByteArray {
+    val out = mutableListOf<Byte>()
+    for (entry in entries) {
+        val bytes = entry.toByteArray(Charsets.UTF_8)
+        out.add(0x0A.toByte())
+        var n = bytes.size
+        while (n >= 0x80) {
+            out.add(((n and 0x7F) or 0x80).toByte())
+            n = n ushr 7
+        }
+        out.add(n.toByte())
+        for (b in bytes) out.add(b)
+    }
+    return out.toByteArray()
+}
+
 fun configurationsResult(configurations: Array<Configuration> = emptyArray()) = Configurations().apply {
     serverToken = "unknown"
     snapshotToken = "unknown"