Migrate CustomLineHeightSpanTest to kotlin (#38847)

Summary:
Migrate `CustomLineHeightSpanTest` to kotlin as part of ☂️ #38825

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[Internal] [Changed] - Migrate CustomLineHeightSpanTest to kotlin

Pull Request resolved: #38847

Test Plan:
```
./gradlew :packages:react-native:ReactAndroid:test
```

Reviewed By: rshest

Differential Revision: D48155397

Pulled By: cortinico

fbshipit-source-id: bbaa7d08a84c609bc64b48a08e1b91078ce6ef23

packages/react-native/ReactAndroid/src/test/java/com/facebook/react/views/text/CustomLineHeightSpanTest.kt

@@ -0,0 +1,121 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.react.views.text
+
+import android.graphics.Paint
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.powermock.core.classloader.annotations.PowerMockIgnore
+import org.robolectric.RobolectricTestRunner
+
+@RunWith(RobolectricTestRunner::class)
+@PowerMockIgnore("org.mockito.*", "org.robolectric.*", "androidx.*", "android.*")
+class CustomLineHeightSpanTest {
+
+  @Test
+  fun evenLineHeightShouldIncreaseAllMetricsProportionally() {
+    val customLineHeightSpan = CustomLineHeightSpan(22f)
+    val fm =
+        Paint.FontMetricsInt().apply {
+          top = -10
+          ascent = -5
+          descent = 5
+          bottom = 10
+        }
+    customLineHeightSpan.chooseHeight("Hi", 0, 2, 0, 0, fm)
+    assertThat(fm.top).isEqualTo(-11)
+    assertThat(fm.ascent).isEqualTo(-11)
+    assertThat(fm.descent).isEqualTo(11)
+    assertThat(fm.bottom).isEqualTo(11)
+    assertThat(fm.bottom - fm.top).isEqualTo(22)
+  }
+
+  @Test
+  fun oddLineHeightShouldAlsoWork() {
+    val customLineHeightSpan = CustomLineHeightSpan(23f)
+    val fm =
+        Paint.FontMetricsInt().apply {
+          top = -10
+          ascent = -5
+          descent = 5
+          bottom = 10
+        }
+    customLineHeightSpan.chooseHeight("Hi", 0, 2, 0, 0, fm)
+    assertThat(fm.descent - fm.ascent).isEqualTo(23)
+    assertThat(fm.bottom - fm.top).isEqualTo(23)
+  }
+
+  @Test
+  fun shouldReduceTopFirst() {
+    val customLineHeightSpan = CustomLineHeightSpan(19f)
+    val fm =
+        Paint.FontMetricsInt().apply {
+          top = -10
+          ascent = -5
+          descent = 5
+          bottom = 10
+        }
+    customLineHeightSpan.chooseHeight("Hi", 0, 2, 0, 0, fm)
+    assertThat(fm.top).isEqualTo(-9)
+    assertThat(fm.ascent).isEqualTo(-5)
+    assertThat(fm.descent).isEqualTo(5)
+    assertThat(fm.bottom).isEqualTo(10)
+  }
+
+  @Test
+  fun shouldReduceBottomSecond() {
+    val customLineHeightSpan = CustomLineHeightSpan(14f)
+    val fm =
+        Paint.FontMetricsInt().apply {
+          top = -10
+          ascent = -5
+          descent = 5
+          bottom = 10
+        }
+    customLineHeightSpan.chooseHeight("Hi", 0, 2, 0, 0, fm)
+    assertThat(fm.top).isEqualTo(-5)
+    assertThat(fm.ascent).isEqualTo(-5)
+    assertThat(fm.descent).isEqualTo(5)
+    assertThat(fm.bottom).isEqualTo(9)
+  }
+
+  @Test
+  fun shouldReduceAscentThird() {
+    val customLineHeightSpan = CustomLineHeightSpan(9f)
+    val fm =
+        Paint.FontMetricsInt().apply {
+          top = -10
+          ascent = -5
+          descent = 5
+          bottom = 10
+        }
+    customLineHeightSpan.chooseHeight("Hi", 0, 2, 0, 0, fm)
+    assertThat(fm.top).isEqualTo(-4)
+    assertThat(fm.ascent).isEqualTo(-4)
+    assertThat(fm.descent).isEqualTo(5)
+    assertThat(fm.bottom).isEqualTo(5)
+  }
+
+  @Test
+  fun shouldReduceDescentLast() {
+    val customLineHeightSpan = CustomLineHeightSpan(4f)
+    val fm =
+        Paint.FontMetricsInt().apply {
+          top = -10
+          ascent = -5
+          descent = 5
+          bottom = 10
+        }
+    customLineHeightSpan.chooseHeight("Hi", 0, 2, 0, 0, fm)
+    assertThat(fm.top).isEqualTo(0)
+    assertThat(fm.ascent).isEqualTo(0)
+    assertThat(fm.descent).isEqualTo(4)
+    assertThat(fm.bottom).isEqualTo(4)
+  }
+}