1. Set Android: shared userid = "android.uid.system" in AndroidManifest.xml
2. After compiling, export unsigned apk.
3. Use \ out \ host \ Linux-x86 \ framework \ signapk.jar \ build \ target \ product \ security \ platform.pk8+platform.x509.pem.
4. execute "Java-jar sign apk.jar platform.x509.pemplatform.pk8test.apk test signed. apk" to sign the platform, and get test signed.apk. ..
Test.apk must be placed in the same directory above.