IssueTracker

Please describe your issue and include details such as the version of CameraX you are using and any relevant logs related to your issue.

// If at all possible, capture an Android logcat (https://developer.android.com/studio/command-line/logcat) when you're experiencing the issue, preferably while the camera is still active.

CAMERAX VERSION (ex - 1.0.0-alpha07)
androidx.camera:camera-camera2:1.0.0-beta05
androidx.camera:camera-lifecycle:1.0.0-beta05
androidx.camera:camera-view:1.0.0-alpha12

CAMERA APPLICATION NAME AND VERSION: (Settings > Apps > (app name) > version)
1.0

ANDROID OS BUILD NUMBER: (Settings > About > Build number)
R16NW.G930VVRU8CRJ3

DEVICE NAME: (Nexus 5X, Samsung S6, etc)
Samsung Galaxy S7 (SM-G930V)

DESCRIPTION:
Tap to focus (via startFocusAndMetering()) only works a few times. Anywhere between 2 and 4 times before it stops actually focusing the requested point. Instead of focusing on the requested point it clearly makes an attempt and then reverts back to the original focus point. Equivalent behavior to attempting to focus on an object too close.
See screenshot to see the screen I'm testing with. Phone is on a stand, focusing another smaller stand.

LIST ANY EXPERIMENTAL FEATURES: (As an example - @ExperimentalCamera2Interop)
Unaware of any.

STEPS TO REPRODUCE:
1. Add tap to focus
2. Run app
3. Tap on an object far away
4. Tap on an object nearby
5. Repeat step 3-4 until it stops working (usually stops working after 2 changes to focus)

OBSERVED RESULTS:
The lens blurs for a second or so as it attempts to focus the requested point, then reverts back to original focus point.

EXPECTED RESULTS:
The lens blurs for a second and then focuses on the requested point

REPRODUCIBILITY: (5 of 5, 1 of 100, etc)
5 of 5 (100%)

ADDITIONAL INFORMATION:
I have attempted to add a call to cancelFocusAndMetering() (and using the future to await the completion) prior to calling startFocusAndMetering() to no avail.
The code I used is adapted from the official recommended way of doing tap to focus, including trying to add disableAutoCancel() since I saw it mentioned in one of the issues reported by another user in here. I tried the following:
1. Calling cancelFocusAndMetering prior
2. Adding .disableAutoCancel() to the action builder
3. Checking that the coordinates are accurate (they are)
4. Searching for similar issues
5. Searching the github sample code for any examples of tap to focus (there are none)
5. Disabling the scaleDetector code but ensuring we only focus once (on ACTION_UP)
Sometimes it seems to recover after a while. I'm not entirely sure what triggers it but it may be related to autofocus.

CODE FRAGMENTS (this will help us troubleshoot your issues):
```
viewFinder.setOnTouchListener { v, event ->
    if (event.action != MotionEvent.ACTION_UP) {
        return@setOnTouchListener scaleDetector.onTouchEvent(event)
    }

    val camera = camera ?: return@setOnTouchListener true

    // Create a factory for creating a MeteringPoint
    val factory = viewFinder.createMeteringPointFactory(cameraSelector)

    // Convert UI coordinates into camera sensor coordinates
    val point = factory.createPoint(event.x, event.y)

    // Prepare focus action to be triggered
    val action = FocusMeteringAction.Builder(point)
        .disableAutoCancel()
        .build()

    // Execute focus action
    camera.cameraControl.startFocusAndMetering(action).addListener(Runnable {
        Log.d(TAG, "Focused at ${point.x} x ${point.y}.")
    }, cameraExecutor)

    v.performClick();
}
```