.apkファイルの中の署名鍵を消しましょう。
$ jarsigner -verbose -keystore app/myapp.keystore app/build/outputs/apk/app-release.apk myapp Enter Passphrase for keystore: jarsigner: unable to sign jar: java.util.zip.ZipException: invalid entry compressed size (expected 20224 but got 20510 bytes) $ zip -d app/build/outputs/apk/app-release.apk META-INF/\* deleting: META-INF/CERT.RSA deleting: META-INF/CERT.SF deleting: META-INF/MANIFEST.MF