manager: new zygisk detection method implemented and deprecated old method

Currently only supports ReZygisk and soon ZygiskNext will hopefully follow (ZN users will have issues detecting zygisk injections until then)

manager/app/src/main/cpp/jni.cc

@@ -320,3 +320,9 @@ JNIEXPORT jboolean JNICALL
 Java_com_rifsxd_ksunext_Natives_setSuEnabled(JNIEnv *env, jobject thiz, jboolean enabled) {
     return set_su_enabled(enabled);
 }
+
+extern "C"
+JNIEXPORT jboolean JNICALL
+Java_com_rifsxd_ksunext_Natives_isZygiskEnabled(JNIEnv *env, jobject) {
+    return is_zygisk_enabled();
+}

manager/app/src/main/cpp/ksu.cc

@@ -6,6 +6,7 @@
 #include <stdint.h>
 #include <string.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <unistd.h>
 
 #include "ksu.h"
@@ -113,3 +114,7 @@ bool is_su_enabled() {
     ksuctl(CMD_IS_SU_ENABLED, &enabled, nullptr);
     return enabled;
 }
+
+bool is_zygisk_enabled() {
+    return !!getenv("ZYGISK_ENABLED");
+}

manager/app/src/main/cpp/ksu.h

@@ -87,4 +87,6 @@ bool set_su_enabled(bool enabled);
 
 bool is_su_enabled();
 
+bool is_zygisk_enabled();
+
 #endif //KERNELSU_KSU_H