Proprietary license incorrectly detected as `bsd-source-code`

### Description

The following proprietary license is detected as `bsd-source-code` which is incorrect

```
// Copyright (C) 2020 XYZ, Inc. All rights reserved.
//
// All information contained herein is XYZ confidential.
//
// This software is provided to you pursuant to Software License
// Agreement (SLA) with XYZ Inc ("XYZ"). This software may be
// used only in accordance with the terms of this agreement.
//
// Redistribution and use in source and binary forms, with or without
// modification is strictly prohibited without prior written permission
// from XYZ.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
```

This is the scan result:
```
"files": [
{
"path": "proprietary-license",
"type": "file",
"detected_license_expression": "bsd-source-code",
"detected_license_expression_spdx": "BSD-Source-Code",
"license_detections": [
{
"license_expression": "bsd-source-code",
"detection_log": [
"unknown-intro-followed-by-match"
],
"matches": [
{
"score": 100.0,
"start_line": 5,
"end_line": 6,
"matched_length": 3,
"match_coverage": 100.0,
"matcher": "2-aho",
"license_clues": [],
"percentage_of_license_text": 73.48,
"for_license_detections": [
"bsd_source_code-9c7fc9b6-724b-5eaf-fe83-5726c437540a"
],
"scan_errors": []
}
]
```