Fix dumpsys for appops proxy field

- Make flags is the last parameters in access decipher methods.
  All calling code assumes this.
- Get proxyUid info from the appropriate field
- Don't create proxy entries if uid is invalid
- Fixed some incorrect docs

Test: adb shell dumpsys appops now shows proxy information
Fixes: 141328071
Change-Id: I2f94e9b171133141643e628c9224d8d74ec5ad87