Fix '-u <user id>' handling in 'adb ime enable' and 'adb ime set'

This is a follow up CL to my previous CLs [1][2], which added
'-u <user id>' option to
   adb shell ime enable <ime id>
and
   adb shell ime set <ime id>
respectively.

Those CL had a bug that was introduced during the last round of the
code review when I was addressing a review comment.  As a result,
those two commands simply fail if '-u' or '--user' option is
specified.  With this CL, those we can finally start specifying the
user ID for those two commands.

This CL also fixes a bug that output for
  adb shell ime set -u all <ime id>
are not correctly formatted.

Note that this CL only fixes a bug in debug shell commands. There
should be no user-visible behavior change in end-user use cases.

 [1]: Ia0f873e4589a9fc3f549469e3d1d966640dc2df5
      e177170f
 [2]: I397cf0fb418a395dcafc0ab0d8d4e553b0f2eaab
      099f80ce

Bug: 120784635
Test: Manually tested as follows:
  1. Build aosp_blueline-userdebug and flash it
  2. make -j SoftKeyboard
  3. adb install -r $OUT/system/app/SoftKeyboard/SoftKeyboard.apk
  4. adb shell pm create-user test
  5. adb shell am switch-user 10
  6. adb shell ime disable -u 0 com.example.android.softkeyboard/.SoftKeyboard
     -> Input method com.example.android.softkeyboard/.SoftKeyboard: now disabled for user #0
  7. adb shell ime enable -u 0 com.example.android.softkeyboard/.SoftKeyboard
     -> Input method com.example.android.softkeyboard/.SoftKeyboard: now enabled for user #0
  8. adb shell ime set -u 0 com.example.android.softkeyboard/.SoftKeyboard
     -> Input method com.example.android.softkeyboard/.SoftKeyboard selected for user #0
Test: Manually tested as follows.
  1. Build aosp_blueline-userdebug and flash it
  2. adb shell pm create-user test
  3. adb shell pm create-user restricted_test
  4. adb root
  5. adb shell pm set-user-restriction --user 11 no_debugging_features 1
  6. adb shell am switch-user 10
  7. adb shell am switch-user 11
  8. adb shell am switch-user 0
  9. adb shell ime set -u all com.android.inputmethod.latin/.LatinIME
     -> Input method com.android.inputmethod.latin/.LatinIME selected for user #0
        Input method com.android.inputmethod.latin/.LatinIME selected for user #10
        User #11 is restricted with DISALLOW_DEBUGGING_FEATURES.
 10. adb shell ime disable -u all com.android.inputmethod.latin/.LatinIME
     -> Input method com.android.inputmethod.latin/.LatinIME: now disabled for user #0
        Input method com.android.inputmethod.latin/.LatinIME: now disabled for user #10
        User #11 is restricted with DISALLOW_DEBUGGING_FEATURES.
Change-Id: I4e396519400c0ccd17322fe085b45456621714e7