Suppress the diff for false value of force_attach field (#14057) (#22954)

[upstream:78268de211c5b3834cf4307222bab65c9069b926]

Signed-off-by: Modular Magician <[email protected]>

Author: modular-magician

.changelog/14057.txt

@@ -0,0 +1,3 @@
+```release-note:bug
+compute: fixed forced instance recreation when adding a `attached_disk` with `force_attach` being `false` to `google_compute_instance` 
+```

google/services/compute/resource_compute_instance.go

@@ -66,6 +66,10 @@ func IpCidrRangeDiffSuppress(k, old, new string, d *schema.ResourceData) bool {
 }
 
 func DisksForceAttachDiffSuppress(_, old, new string, _ *schema.ResourceData) bool {
+	if (new == "false" && old == "") || (new == "" && old == "false") {
+		return true
+	}
+
 	if new == old {
 		return true
 	}

google/services/compute/resource_compute_instance_test.go

@@ -132,6 +132,16 @@ func TestDisksForceAttachDiffSuppress(t *testing.T) {
 			New:                "false",
 			ExpectDiffSuppress: true,
 		},
+		"force_attach changed false from empty": {
+			Old:                "",
+			New:                "false",
+			ExpectDiffSuppress: true,
+		},
+		"force_attach changed empty from false": {
+			Old:                "false",
+			New:                "",
+			ExpectDiffSuppress: true,
+		},
 	}
 
 	for tn, tc := range cases {