fix(android): Adapt floor math from Guava

Use Apache-licensed Guava LongMath floor division logic for SentryMath and restore the matching third-party attribution. Keep floorMod implemented through floorDiv so it matches Math.floorMod for negative divisors too.

Co-Authored-By: Claude <noreply@anthropic.com>

Author: adinauer

THIRD_PARTY_NOTICES.md

@@ -34,6 +34,34 @@ limitations under the License.
 
 ---
 
+## Google Guava — LongMath (Apache 2.0)
+
+**Source:** https://github.com/google/guava/blob/v33.0.0/guava/src/com/google/common/math/LongMath.java<br>
+**License:** Apache License 2.0<br>
+**Copyright:** Copyright (C) 2011 The Guava Authors
+
+### Scope
+
+The Sentry Java SDK includes adapted floor division logic from Guava's `LongMath` class to support older Android API levels. The code resides in `io.sentry.vendor.SentryMath`.
+
+```
+Copyright (C) 2011 The Guava Authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+```
+
+---
+
 ## FasterXML Jackson — ISO8601Utils (Apache 2.0)
 
 **Source:** https://github.com/FasterXML/jackson-databind<br>

sentry/src/main/java/io/sentry/vendor/SentryMath.java

@@ -1,3 +1,21 @@
+/*
+ * Adapted from https://github.com/google/guava/blob/v33.0.0/guava/src/com/google/common/math/LongMath.java
+ *
+ * Copyright (C) 2011 The Guava Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package io.sentry.vendor;
 
 final class SentryMath {
@@ -6,16 +24,17 @@ private SentryMath() {}
 
   static long floorDiv(final long x, final long y) {
     final long quotient = x / y;
-    final long remainder = x % y;
-    return remainder != 0 && hasDifferentSigns(x, y) ? quotient - 1 : quotient;
-  }
+    final long remainder = x - y * quotient;
 
-  static long floorMod(final long x, final long y) {
-    final long remainder = x % y;
-    return remainder != 0 && hasDifferentSigns(x, y) ? remainder + y : remainder;
+    if (remainder == 0) {
+      return quotient;
+    }
+
+    final int signum = 1 | (int) ((x ^ y) >> (Long.SIZE - 1));
+    return signum < 0 ? quotient + signum : quotient;
   }
 
-  private static boolean hasDifferentSigns(final long x, final long y) {
-    return x < 0 != y < 0;
+  static long floorMod(final long x, final long y) {
+    return x - floorDiv(x, y) * y;
   }
 }